subject:(Ab initio)

Cornell University

1. Schwarz, Kathleen. Partitioning Molecular And Surface Environments: Practice And Approximations.

Degree: PhD, Chemistry and Chemical Biology, 2014, Cornell University

► The physics of complex environments, though poorly understood, plays a critical role in a wide range of systems from the biological to the technological. Despite… (more)

▼ The physics of complex environments, though poorly understood, plays a critical role in a wide range of systems from the biological to the technological. Despite the importance of these systems, they are poorly understood. The large required simulation size of complex environments currently makes them unsuitable for direct ab initio calculations, yet inexpensive methods such as molecular modeling can be too approximate to describe the relevant chemical interactions. One resolution to this problem is to accurately describe specific interactions, and to inexpensively approximate interactions which are less relevant. The objective of this thesis is to determine to what extent one can partition systems into a molecule or surface treated at one level of theory, and a surrounding fluid or other molecular environment treated with another theory. I explore varying levels of theory, using different theories depending on the properties of the system and type of problem, and I address conflicts that arise from these choices when working to calculate properties of real systems. In the first project of the thesis, I strategically explore very different levels of theory for the solvent and solute to subvert the typical relationship found in computational work between cost and accuracy. In this thesis chapter, I combine a simple continuum description of a fluid with highly accurate quantum Monte Carlo calculations, to find solvation free energies of molecules. I find that this approach successfully preserves the accuracy of quantum Monte Carlo, while creating a framework for future calculations with more complicated fluid models. In the next two chapters, I investigate the continuum between expensive calculations of realistic systems, and inexpensive idealized systems. I examine the properties of lithium-sulfur battery systems and defects in pentacene thin films, using established polarizable continuum methods and density-functional theory, exploring the extent to which experimental realities alter the relevant observables. I am able to produce idealized voltammograms that capture key aspects of the battery experiments, and I also identify an experimentally observed defect in the pentacene. In the last chapter, I investigate the creation of a whole crystal from the sum of its parts, as I develop approximations of the dielectric matrix in molecular crystals. I successfully apply this to two crystals, creating dielectric band structures from molecular calculations that very closely resemble those from the entire crystal. Advisors/Committee Members: Marohn, John A. (chair), Hennig, Richard G. (committee member), Hoffmann, Roald (committee member), Arias, Tomas A. (committee member).

Subjects/Keywords: ab initio electronic structure; solvation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Schwarz, K. (2014). Partitioning Molecular And Surface Environments: Practice And Approximations. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/37083

Chicago Manual of Style (16^th Edition):

Schwarz, Kathleen. “Partitioning Molecular And Surface Environments: Practice And Approximations.” 2014. Doctoral Dissertation, Cornell University. Accessed April 21, 2021. http://hdl.handle.net/1813/37083.

MLA Handbook (7^th Edition):

Schwarz, Kathleen. “Partitioning Molecular And Surface Environments: Practice And Approximations.” 2014. Web. 21 Apr 2021.

Vancouver:

Schwarz K. Partitioning Molecular And Surface Environments: Practice And Approximations. [Internet] [Doctoral dissertation]. Cornell University; 2014. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/1813/37083.

Council of Science Editors:

Schwarz K. Partitioning Molecular And Surface Environments: Practice And Approximations. [Doctoral Dissertation]. Cornell University; 2014. Available from: http://hdl.handle.net/1813/37083

Universidade de Brasília

2. Elton Anderson Santos de Castro. Estudo teórico da adsorção em aluminossilicatos.

Degree: 2007, Universidade de Brasília

URL: http://bdtd.bce.unb.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=2713

► Foram realizados cálculos de mecânica molecular, semi-empíricos e ab initio para o estudo de sistemas baseados em caulinita. As posições e freqüências dos hidrogênios foram… (more)

▼ Foram realizados cálculos de mecânica molecular, semi-empíricos e ab initio para o estudo de sistemas baseados em caulinita. As posições e freqüências dos hidrogênios foram estudadas na estrutura da caulinita. As posições dos hidrogênios são polêmicas, principalmente os hidrogênios entre as folhas octaédrica e tetraédrica. Também estudou-se a interação deste argilomineral com os hidrocarbonetos monoaromáticos benzeno, tolueno, etilbenzeno, o-xileno e pxileno, bem como com os metais pesados Cd2+, Cu2+, Zn2+, Hg2+ e Ni2+. A caulinita é conhecida pela sua capacidade adsorvente para moléculas orgânicas e metais pesados, sendo importante em técnicas de remediação ambiental. Modelos de aglomerados com 1, 2 e 3 unidades (Al2Si2O9H4) foram usados para estudar o desempenho dos conjuntos de base. A geometria da caulinita foi parcialmente otimizada. Para a otimização da posição do hidrogênio interno empregou-se os métodos RHF/3-21G* e B3LYP/3-21G* com 2 e 3 unidades (Al2Si2O9H4) da caulinita. O método híbrido ONIOM também foi usado com 3 unidades (Al2Si2O9H4) e RHF/3-21G* (ou B3LYP/3-21G*) na camada alta e 12 unidades (Al2Si2O9H4) e o campo de força Dreiding na camada baixa de teoria. Quando comparados com os valores experimentais, os resultados dos cálculos indicam que o ONIOM2(B3LYP/3-21G*:Dreiding) dá os melhores valores para a distância O-H e ângulos r e l, 0,993Å, 114,8 e 107,6, respectivamente. Os cálculos de freqüência para os hidrogênios externos e internos com o modelo de 3 unidades (Al2Si2O9H4) mostram que o método RHF/3-21G* se aproxima mais dos resultados experimentais do que os semi-empíricos AM1 e PM3. Estes três métodos apontam para um estiramento da hidroxila interna num número de onda menor do que os das hidroxilas externas. Os espectros teóricos produzidos com o AM1 mostram que há uma redução nas intensidades das bandas de estiramento das hidroxilas externas quando estas interagem com as moléculas BTEX. Também foi encontrado um deslocamento nas bandas de estiramento C-H destas moléculas. As energias de interação, obtidas com os métodos AM1, RHF e B3LYP para os complexos BTEX-Caulinita, sugerem que a adsorção acontece preferencialmente pela superfície hidroxilada da caulinita, ao invés da superfície dos oxigênios. Os métodos de Mülliken e ChelpG indicam que ocorre uma redistribuição nas cargas dos átomos mais próximos das superfícies da caulinita, ficando os hidrogênios mais eletronegativos e os carbonos, mais eletropositivos. Os mapas de potencial eletrostático para os complexos BTEX-Caulinita mostram também uma redistribuição de densidade quando as moléculas interagem com a superfície do argilomineral, corroborando com os resultados de Mülliken e ChelpG. Os orbitais moleculares do benzeno, tolueno e o-xileno adsorvidos pela caulinita sugerem que esta interação acontece através da nuvem p dos compostos aromáticos com as hidroxilas externas da caulinita. Para o estudo dos complexos de metais pesados-caulinita foi usado o ONIOM2(HF/3-21G*:UFF) e ONIOM2(B3LYP/3-21G*:UFF). Para estes modelos da caulinita de 2… Advisors/Committee Members: Ricardo Gargano, Sílvia Cláudia Loureiro Dias, João Batista Lopes Martins, Jose Roberto dos Santos Politi, Elson Longo.

Subjects/Keywords: caulinita; adsorção; ab initio; QUIMICA

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Castro, E. A. S. d. (2007). Estudo teórico da adsorção em aluminossilicatos. (Thesis). Universidade de Brasília. Retrieved from http://bdtd.bce.unb.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=2713

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Castro, Elton Anderson Santos de. “Estudo teórico da adsorção em aluminossilicatos.” 2007. Thesis, Universidade de Brasília. Accessed April 21, 2021. http://bdtd.bce.unb.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=2713.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Castro, Elton Anderson Santos de. “Estudo teórico da adsorção em aluminossilicatos.” 2007. Web. 21 Apr 2021.

Vancouver:

Castro EASd. Estudo teórico da adsorção em aluminossilicatos. [Internet] [Thesis]. Universidade de Brasília; 2007. [cited 2021 Apr 21]. Available from: http://bdtd.bce.unb.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=2713.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Castro EASd. Estudo teórico da adsorção em aluminossilicatos. [Thesis]. Universidade de Brasília; 2007. Available from: http://bdtd.bce.unb.br/tedesimplificado/tde_busca/arquivo.php?codArquivo=2713

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

King Abdullah University of Science and Technology

3. Albar, Arwa. Defect Engineering and Interface Phenomena in Tin Oxide.

Degree: Physical Science and Engineering (PSE) Division, 2017, King Abdullah University of Science and Technology

URL: http://hdl.handle.net/10754/623128

► The advance in transparent electronics requires high-performance transparent conducting oxide materials. The microscopic properties of these materials are sensitive to the presence of defects and… (more)

▼ The advance in transparent electronics requires high-performance transparent conducting oxide materials. The microscopic properties of these materials are sensitive to the presence of defects and interfaces and thus fundamental understanding is required for materials engineering. In this thesis, first principles density functional theory is used to investigate the possibility of tuning the structural, electronic and magnetic properties of tin oxide by means of defects and interfaces. Our aim is to reveal unique properties and the parameters to control them as well as to explain the origin of unique phenomena in oxide materials. The stability of native defect in tin monoxide (SnO) under strain is investigated using formation energy calculations. We find that the conductivity (which is controlled by native defects) can be switched from p-type to either n-type or undoped semiconducting by means of applied pressure. We then target inducing magnetism in SnO by 3d transition metal doping. We propose that V doping is efficient to realize spin polarization at high temperature. We discuss different tin oxide interfaces. Metallic states are found to form at the SnO/SnO2 interface with electronic properties that depend on the interface terminations. The origin of these states is explained in terms of charge transfer caused by chemical bonding and band alignment. For the SnO/SnO2 heterostructure, we observe the formation of a two dimensional hole gas at the interface, which is surprising as it cannot be explained by the standard polar catastrophe model. Thus, we propose a charge density discontinuity model to explain our results. The model can be generalized to other polar-polar interfaces. Motivated by technological applications, the electronic and structural properties of the MgO (100)/SnO2 (110) interface are investigated. Depending on the interface termination, we observe the formation of a two dimensional electron gas or spin polarized hole gas. Aiming to identify further key parameters, we examine O deficient LaAlO3/SrTiO3 (110) and (001) superlattices under hydrostatic pressure. Presence of O vacancies results in formation of a two-dimensional electron gas, for which we observe a distinct spatial pattern of carrier density that depends strongly on the amount of applied pressure. Advisors/Committee Members: Schwingenschlögl, Udo (advisor), Alshareef, Husam N. (committee member), Hussain, Muhammad Mustafa (committee member), Aljawhari, Hala (committee member).

Subjects/Keywords: Ab-initio; Oxides; Defects; Interfaces

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Albar, A. (2017). Defect Engineering and Interface Phenomena in Tin Oxide. (Thesis). King Abdullah University of Science and Technology. Retrieved from http://hdl.handle.net/10754/623128

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Albar, Arwa. “Defect Engineering and Interface Phenomena in Tin Oxide.” 2017. Thesis, King Abdullah University of Science and Technology. Accessed April 21, 2021. http://hdl.handle.net/10754/623128.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Albar, Arwa. “Defect Engineering and Interface Phenomena in Tin Oxide.” 2017. Web. 21 Apr 2021.

Vancouver:

Albar A. Defect Engineering and Interface Phenomena in Tin Oxide. [Internet] [Thesis]. King Abdullah University of Science and Technology; 2017. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/10754/623128.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Albar A. Defect Engineering and Interface Phenomena in Tin Oxide. [Thesis]. King Abdullah University of Science and Technology; 2017. Available from: http://hdl.handle.net/10754/623128

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Universidade do Rio Grande do Norte

4. Medeiros, Subênia Karine de. Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3 .

Degree: 2007, Universidade do Rio Grande do Norte

URL: http://repositorio.ufrn.br/handle/123456789/16649

► The physical properties and the excitations spectrum in oxides and semiconductors materials are presented in this work, whose the first part presents a study on… (more)

▼ The physical properties and the excitations spectrum in oxides and semiconductors materials are presented in this work, whose the first part presents a study on the confinement of optical phonons in artificial systems based on III-V nitrides, grown in periodic and quasiperiodic forms. The second part of this work describes the Ab initio calculations which were carried out to obtain the optoeletronic properties of Calcium Oxide (CaO) and Calcium Carbonate (CaCO3) crystals. For periodic and quasi-periodic superlattices, we present some dynamical properties related to confined optical phonons (bulk and surface), obtained through simple theories, such as the dielectric continuous model, and using techniques such as the transfer-matrix method. The localization character of confined optical phonon modes, the magnitude of the bands in the spectrum and the power laws of these structures are presented as functions of the generation number of sequence. The ab initio calculations have been carried out using the CASTEP software (Cambridge Total Sequential Energy Package), and they were based on ultrasoft-like pseudopotentials and Density Functional Theory (DFT). Two di®erent geometry optimizations have been e®ectuated for CaO crystals and CaCO3 polymorphs, according to LDA (local density approximation) and GGA (generalized gradient approximation) approaches, determining several properties, e. g. lattice parameters, bond length, electrons density, energy band structures, electrons density of states, e®ective masses and optical properties, such as dielectric constant, absorption, re°ectivity, conductivity and refractive index. Those results were employed to investigate the confinement of excitons in spherical [email protected] and [email protected] quantum dots and in calcium carbonate nanoparticles, and were also employed in investigations of the photoluminescence spectra of CaCO3 crystal Advisors/Committee Members: Albuquerque, Eudenilson Lins de (advisor), CPF:05011124487 (advisor), http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4783172H5 (advisor), Freire, Valder Nogueira (advisor), CPF:12105473334 (advisor), http://lattes.cnpq.br/8647922327100953 (advisor).

Subjects/Keywords: Heteroestruturas; Hidretos; Ab initio; Nanoescalas; Heterostructures; Hydrides; Ab initio; Nanoscales

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Medeiros, S. K. d. (2007). Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3 . (Thesis). Universidade do Rio Grande do Norte. Retrieved from http://repositorio.ufrn.br/handle/123456789/16649

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Medeiros, Subênia Karine de. “Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3 .” 2007. Thesis, Universidade do Rio Grande do Norte. Accessed April 21, 2021. http://repositorio.ufrn.br/handle/123456789/16649.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Medeiros, Subênia Karine de. “Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3 .” 2007. Web. 21 Apr 2021.

Vancouver:

Medeiros SKd. Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3 . [Internet] [Thesis]. Universidade do Rio Grande do Norte; 2007. [cited 2021 Apr 21]. Available from: http://repositorio.ufrn.br/handle/123456789/16649.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Medeiros SKd. Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3 . [Thesis]. Universidade do Rio Grande do Norte; 2007. Available from: http://repositorio.ufrn.br/handle/123456789/16649

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

5. Subênia Karine de Medeiros. Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3.

Degree: 2007, Universidade Federal do Rio Grande do Norte

URL: http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=1189

►

The physical properties and the excitations spectrum in oxides and semiconductors materials are presented in this work, whose the first part presents a study on… (more)

▼

The physical properties and the excitations spectrum in oxides and semiconductors materials are presented in this work, whose the first part presents a study on the confinement of optical phonons in artificial systems based on III-V nitrides, grown in periodic and quasiperiodic forms. The second part of this work describes the Ab initio calculations which were carried out to obtain the optoeletronic properties of Calcium Oxide (CaO) and Calcium Carbonate (CaCO3) crystals. For periodic and quasi-periodic superlattices, we present some dynamical properties related to confined optical phonons (bulk and surface), obtained through simple theories, such as the dielectric continuous model, and using techniques such as the transfer-matrix method. The localization character of confined optical phonon modes, the magnitude of the bands in the spectrum and the power laws of these structures are presented as functions of the generation number of sequence. The ab initio calculations have been carried out using the CASTEP software (Cambridge Total Sequential Energy Package), and they were based on ultrasoft-like pseudopotentials and Density Functional Theory (DFT). Two dierent geometry optimizations have been eectuated for CaO crystals and CaCO3 polymorphs, according to LDA (local density approximation) and GGA (generalized gradient approximation) approaches, determining several properties, e. g. lattice parameters, bond length, electrons density, energy band structures, electrons density of states, eective masses and optical properties, such as dielectric constant, absorption, reectivity, conductivity and refractive index. Those results were employed to investigate the confinement of excitons in spherical [email protected] and [email protected] quantum dots and in calcium carbonate nanoparticles, and were also employed in investigations of the photoluminescence spectra of CaCO3 crystal

As propriedades físicas e o espectro de excitações em materiais óxidos e semicondutores são apresentados neste trabalho, composto primeiramente por um estudo sobre o confinamento de fonons ópticos em sistemas artificiais baseados em nitretos III-V, crescidos periodicamente e quasi-periodicamente. A segunda parte deste trabalho descreve cálculos de primeiros princípios realizados para a obtenção de propriedades optoeletrônicas em cristais de Óxido de Cálcio (CaO) e Carbonato de Cálcio (CaCO3). Para as super- redes periódicas e quasi-periódicas apresentamos aqui algumas propriedades dinâmicas relacionadas a fonons ópticos (de volume e de superfície) confinados obtidos através de teorias simples como o modelo do dielétrico contínuo e a utilização de técnicas como a aproximação da matriz transferência. O caráter de localização dos modos de fonons ópticos confinados, a magnitude das bandas no espectro e a lei de escalas dessas estruturas como função do número de geração das sequências substitucionais são apresentadas. Os cálculos ab initio foram realizados utilizando o software CASTEP (Cambridge Sequential Total Energy Package) baseados nos métodos de…

Advisors/Committee Members: Ewerton Wagner Caetano, Valder Nogueira Freire, Dory Hélio Aires de Lima Anselmo, Luciano Rodrigues da Silva, Eudenilson Lins de Albuquerque.

Subjects/Keywords: Ab initio; Heteroestruturas; Hidretos; Nanoescalas; FISICA; Heterostructures; Hydrides; Ab initio; Nanoscales

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Medeiros, S. K. d. (2007). Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3. (Thesis). Universidade Federal do Rio Grande do Norte. Retrieved from http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=1189

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Medeiros, Subênia Karine de. “Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3.” 2007. Thesis, Universidade Federal do Rio Grande do Norte. Accessed April 21, 2021. http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=1189.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Medeiros, Subênia Karine de. “Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3.” 2007. Web. 21 Apr 2021.

Vancouver:

Medeiros SKd. Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3. [Internet] [Thesis]. Universidade Federal do Rio Grande do Norte; 2007. [cited 2021 Apr 21]. Available from: http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=1189.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Medeiros SKd. Sistemas Nanoestruturados: Heteroestruturas Quasi-Periódicas de Nitretos e Cálculos Ab initio em Polimorfos CaCO3. [Thesis]. Universidade Federal do Rio Grande do Norte; 2007. Available from: http://bdtd.bczm.ufrn.br/tedesimplificado//tde_busca/arquivo.php?codArquivo=1189

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

6. Florence Pereira Novais Antunes. Estudo ab initio da adsorção de organofosforados em TiO2 e Ti(1-x)ZrxO2.

Degree: 2010, Universidade Federal de Juiz de Fora

URL: http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=739

►

O estudo da degradação de organofosforados é de suma importância tanto na área ambiental quanto na de defesa química. Tem sido descrito na literatura exaustivos… (more)

▼

O estudo da degradação de organofosforados é de suma importância tanto na área ambiental quanto na de defesa química. Tem sido descrito na literatura exaustivos estudos sobre degradação de organofosforados relacionados à agricultura. Um desses estudos leva em conta o uso da luz na degradação de um dos organofosforados mais usados na agricultura como pesticida, o paration. O processo chamado de fotocátalise heterogênea, envolve a ativação de um semicondutor (geralmente TiO2) por luz solar ou artificial. A absorção de fótons com energia superior à energia de bandgap resulta na promoção de um elétron da banda de valência para banda de condução com geração concomitante de um buraco (hole) na banda de valência. Estes buracos mostram potenciais suficientemente positivos, capazes de formar radicais hidroxila a partir de moléculas de água adsorvidas na superfície do semicondutor, os quais podem subseqüentemente oxidar contaminantes orgânicos. O objetivo deste trabalho foi determinar a influência da substituição de titânio por zircônio em TiO2 na adsorção de organofosforados, que é uma das etapas de degradação desses compostos. Para isso foram determinadas as estruturas, propriedades eletrônicas e vibracionais de organofosforados adsorvidos em TiO2 (101) anatase e Ti(1-x)ZrxO2. Os compostos estudados e adsorvidos são: Paration, Sarin e VX. A idéia foi propor uma técnica bem descrita experimentalmente para degradação do paration, para possível detoxificação de organofosforados usados como armas químicas, no caso, o Sarin e o VX. Foi feito o estudo da adsorção dos organofosforados em titânia substituída com zircônio na proporção Ti(1-x)ZrxO2, levando em conta que modificações na estrutura do catalisador aumentam a atividade fotocatalítica. Cálculos feitos verificam a contribuição energética da etapa de adsorção e comparando com a estrutura do catalisador puro foi possível obter melhora nesta etapa. Foram obtidas energias de fisissorção e quimissorção nas diferentes posições possíveis. O tipo de adsorção foi confirmado com estudos de diferença de carga eletrônica. Foi obtido também o estudo de frequência vibracional. A partir dos resultados, concluiu-se que a adsorção se processou de maneira mais efetiva nos casos em que foi usado o catalisador com zircônio, com energia de adsorção de -25,71kcal/mol, para o p-VX adsorvido. Em titânia pura a energia de adsorção de p-VX foi de -18,14kcal/mol. As diferenças de densidade de carga eletrônica também confirmaram os resultados

The study of degradation of organophosphorous is critical both in the environmental area as in chemical defense. Has been described in the literature studies on degradation of organophosphorous related to agriculture. One of the study considers the use of light in a degradation of the organophosphorous pesticide used in agriculture: the parathion. The process called heterogeneous photocatalysis involves the activation of a semiconductor (usually TiO 2) by sunlight or artificial. The absorption of photons with energy higher than the energy band gap results in…

Advisors/Committee Members: Itamar Borges Junior, Clarissa Oliveira da Silva, Socrates de Oliveira Dantas, Alexandre Amaral Leitao.

Subjects/Keywords: adsorção; FISICO-QUIMICA; ab initio; organofosforados; adsorption; ab initio; organophosphorous

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Antunes, F. P. N. (2010). Estudo ab initio da adsorção de organofosforados em TiO2 e Ti(1-x)ZrxO2. (Thesis). Universidade Federal de Juiz de Fora. Retrieved from http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=739

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Antunes, Florence Pereira Novais. “Estudo ab initio da adsorção de organofosforados em TiO2 e Ti(1-x)ZrxO2.” 2010. Thesis, Universidade Federal de Juiz de Fora. Accessed April 21, 2021. http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=739.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Antunes, Florence Pereira Novais. “Estudo ab initio da adsorção de organofosforados em TiO2 e Ti(1-x)ZrxO2.” 2010. Web. 21 Apr 2021.

Vancouver:

Antunes FPN. Estudo ab initio da adsorção de organofosforados em TiO2 e Ti(1-x)ZrxO2. [Internet] [Thesis]. Universidade Federal de Juiz de Fora; 2010. [cited 2021 Apr 21]. Available from: http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=739.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Antunes FPN. Estudo ab initio da adsorção de organofosforados em TiO2 e Ti(1-x)ZrxO2. [Thesis]. Universidade Federal de Juiz de Fora; 2010. Available from: http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=739

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Universidade Federal do Maranhão

7. ANDRÉ HADAD CORTEZ. PROPRIEDADES ELETRÔNICAS DE NANOFIOS DE SI-GE COM SEQUENCIAMENTO DE FIBONACCI E RANDÔMICO.

Degree: 2012, Universidade Federal do Maranhão

URL: http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=891

►

In this work we address a theoretical calculation of the electronic spectra in Si-Ge atomic chain that is arranged in a Fibonacci quasi-periodic sequence, by… (more)

▼

In this work we address a theoretical calculation of the electronic spectra in Si-Ge atomic chain that is arranged in a Fibonacci quasi-periodic sequence, by using semi-empirical quantum method based on Hückel extended model. We apply the Fibonacci substitutional sequences in the atomic building blocks A(Si) and B(Ge) through the in ation rule or recursion relation. In our ab initio calculations we use only a single point which is the suficient condition to consider all the orbitals and charge distribution across the entire system. Although the calculations presented here are more complete than the models adopted in the literature which take into account the electronic interaction, up to the second and third neighbors, an interesting property remains in their electronic spectra: the fractality (which is the main signature of this kind of system). We discuss this fractality of the spectra and we compare them with the randomic arrangement of Si-Ge atomic chain, and with previous results based on the tight-binding approximation of Schorödinger equation considering until the nearest neighbor.

Neste trabalho abordamos um cálculo teórico dos espectros eletrônicos em cadeia atômica de Si-Ge que e organizado em uma sequência Fibonacci quasi-periódica, usando o método semi-emíprico com base no modelo quântico Hückel estendido. Nos aplicamos as sequências substitucional de Fibonacci nos blocos de construção atômica A(Si) e B(Ge) através da relação de recursão. Em nossos cálculos ab initio, usamos apenas um único ponto, que é a condição suficiente para considerar todos os orbitais e a distribuição de cargas em todo o sistema. Embora os cálculos apresentados aqui sejam mais completos do que os modelos adotados na literatura que levam em conta a interação eletrônica, ate segundos e terceiros vizinhos, uma propriedade interessante permanece em seus espectros eletrônicos: a fractalidade (que e a assinatura principal deste tipo de sistema). Discutimos essa fractalidade dos espectros e as comparamos com os espectros de cadeia atômica randômica de Si-Ge, e, também, com os resultados prévios baseados na aproximação tight-binding da equação Schorödinger considerando até o vizinho mais próximo.

Advisors/Committee Members: David Lima Azevedo.

Subjects/Keywords: Nanofios; Finonacci; Fractalidade; Ab initio; FISICA; Nanowires; Ab initio; Fibonacci; Fractality

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

CORTEZ, A. H. (2012). PROPRIEDADES ELETRÔNICAS DE NANOFIOS DE SI-GE COM SEQUENCIAMENTO DE FIBONACCI E RANDÔMICO. (Thesis). Universidade Federal do Maranhão. Retrieved from http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=891

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

CORTEZ, ANDRÉ HADAD. “PROPRIEDADES ELETRÔNICAS DE NANOFIOS DE SI-GE COM SEQUENCIAMENTO DE FIBONACCI E RANDÔMICO.” 2012. Thesis, Universidade Federal do Maranhão. Accessed April 21, 2021. http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=891.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

CORTEZ, ANDRÉ HADAD. “PROPRIEDADES ELETRÔNICAS DE NANOFIOS DE SI-GE COM SEQUENCIAMENTO DE FIBONACCI E RANDÔMICO.” 2012. Web. 21 Apr 2021.

Vancouver:

CORTEZ AH. PROPRIEDADES ELETRÔNICAS DE NANOFIOS DE SI-GE COM SEQUENCIAMENTO DE FIBONACCI E RANDÔMICO. [Internet] [Thesis]. Universidade Federal do Maranhão; 2012. [cited 2021 Apr 21]. Available from: http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=891.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

CORTEZ AH. PROPRIEDADES ELETRÔNICAS DE NANOFIOS DE SI-GE COM SEQUENCIAMENTO DE FIBONACCI E RANDÔMICO. [Thesis]. Universidade Federal do Maranhão; 2012. Available from: http://www.tedebc.ufma.br//tde_busca/arquivo.php?codArquivo=891

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

8. Khalil, Hossain. Highly accurate studies of the rovibronic states of small size radicals : Etudes très précises des états rovibroniques des radicaux de petites tailles.

Degree: Docteur es, Chimie, 2012, Université Paris-Est

URL: http://www.theses.fr/2012PEST1028

►

Des calculs ab initio basés sur des méthodes hautement corrélées ont été utilisés pour étudier la structure rovibronique et la spectroscopie des radicaux de 2… (more)

▼

Des calculs ab initio basés sur des méthodes hautement corrélées ont été utilisés pour étudier la structure rovibronique et la spectroscopie des radicaux de 2 à 4 atomes. Pour les molécules CaO, OH, CaH, CaO+ et CaO-, les constantes spectroscopiques calculées sont en accord avec les données expérimentales. L'étude de ces fragments diatomiques est essentielle pour comprendre la structure électronique des isomères du monohydroxyde de calcium (CaOH-HCaO). Le système le plus complexe, parmi ces radicaux diatomiques, est le monoxyde de calcium CaO en raison de la densité élevée des premiers états électroniques. Les énergies rovibrationnelles de ces états ont été calculées sur la base des énergies potentielles obtenues avec un niveau élevé de précision, en tenant compte des couplages entre les moments angulaires et du couplage spin-orbite. Nos résultats sont très proches des résultats expérimentaux. La complexité de l'étude d'un tel système est aussi présente dans le radical ketenyl HCCO à cause de l'effet Renner-Teller qui couple l'état fondamental et le premier état excité. L'effet Renner-Teller dans HCCO a été étudié à l'aide d'une approche variationnelle traitant tous les degrés de liberté. Les coordonnées de valence ont été utilisées pour construire les deux surfaces d'énergie potentielle à six dimensions. Les niveaux rovibroniques les plus bas ont été obtenus pour différentes valeurs du moment angulaire total

Highly correlated ab initio methodologies were used to investigate the rovibronic structure and the spectroscopy of 2 to 4 atoms radicals. For the CaO, OH, CaH, CaO+ and CaO− molecules, our computed spectroscopic constants are in good agreement with the experimental ones. The study of these diatomic fragments is essential to investigate the calcium monohydroxide isomers (CaOH-HCaO). The most complex system among these diatomic radicals is the calcium monoxide radical CaO due to high density low lying electronic states. The rovibrational energies of these states have been calculated, based on the potential energies obtained at high level of accuracy, taking into account the angular momentum and spin orbit couplings and found to be in a very good agreement with the experimental results. The complexity in studying such a system is again present in the ketenyl radical HCCO with highly coupled ground and first excited states. The Renner-Teller effect of HCCO is studied using a variational approach including all degrees of freedom. Valence coordinates have been used to fit both potential energy surfaces varying the six degrees of freedom. The low-lying rovibronic levels have been determined for different values of the total angular momentum

Advisors/Committee Members: Destandau-Léonard, Céline (thesis director).

Subjects/Keywords: Ab initio; Spectroscopie; Rovibronique; Ab initio; Spectroscopy; Rovibronic

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Khalil, H. (2012). Highly accurate studies of the rovibronic states of small size radicals : Etudes très précises des états rovibroniques des radicaux de petites tailles. (Doctoral Dissertation). Université Paris-Est. Retrieved from http://www.theses.fr/2012PEST1028

Chicago Manual of Style (16^th Edition):

Khalil, Hossain. “Highly accurate studies of the rovibronic states of small size radicals : Etudes très précises des états rovibroniques des radicaux de petites tailles.” 2012. Doctoral Dissertation, Université Paris-Est. Accessed April 21, 2021. http://www.theses.fr/2012PEST1028.

MLA Handbook (7^th Edition):

Khalil, Hossain. “Highly accurate studies of the rovibronic states of small size radicals : Etudes très précises des états rovibroniques des radicaux de petites tailles.” 2012. Web. 21 Apr 2021.

Vancouver:

Khalil H. Highly accurate studies of the rovibronic states of small size radicals : Etudes très précises des états rovibroniques des radicaux de petites tailles. [Internet] [Doctoral dissertation]. Université Paris-Est; 2012. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2012PEST1028.

Council of Science Editors:

Khalil H. Highly accurate studies of the rovibronic states of small size radicals : Etudes très précises des états rovibroniques des radicaux de petites tailles. [Doctoral Dissertation]. Université Paris-Est; 2012. Available from: http://www.theses.fr/2012PEST1028

9. Maatouk, Amira. Étude de la croissance des nanotubes de carbone catalysée par le fer : Structures and properties of small iron-doped carbon clusters.

Degree: Docteur es, Chimie, 2012, Université Paris-Est

URL: http://www.theses.fr/2012PEST1147

► L’étude de réactions chimiques, tout comme le calcul de propriétés thermodynamiques, sont des enjeux capitaux de la chimie moderne. L’évolution des instruments et techniques expérimentales… (more)

▼ L’étude de réactions chimiques, tout comme le calcul de propriétés thermodynamiques, sont des enjeux capitaux de la chimie moderne. L’évolution des instruments et techniques expérimentales permet des mesures de plus en plus précises de ces grandeurs, pour des systèmes de plus en plus complexes. L’intérêt croissant pour l’étude du milieu interstellaire et des atmosphères planétaires se révèle également être un défi très important dans les décennies à venir. Les difficultés rencontrées lors de l’analyse de ces expériences (ou mesures), nécessitent souvent l’intervention de simulations numériques de manière à éclairer ces observations. Une autre utilisation du calcul est de prédire des paramètres moléculaires et spectroscopiques d’espèces instables difficiles à produire au laboratoire. Les outils actuels de la chimie théorique ab initio sont des moyens précieux pour la prédiction et l’interprétation de résultats expérimentaux ou de mesures astrophysiques et atmosphériques. Ces techniques de simulation ont connu des développements importants au cours des dernières décennies. Les progrès récents en matière de calculs d’interaction de configurations de grande taille permettent d’inclure une grande partie de l’énergie de corrélation. Le temps de calcul et la taille mémoire des ordinateurs restent cependant des limites importantes qui ne permettent pas d’effectuer des interactions de configurations totales dans une base suffisamment grande pour contenir la physique des systèmes étudiés au delà de petites molécules. Cet état de fait conduit à s’intéresser à des méthodes moins coûteuses comme celles des perturbations, les interactions de configurations tronquées et le Coupled Cluster, permettant d’inclure une partie de la corrélation électronique à un coût moins élevé en temps de calcul. Ce sont ces méthodes qui ont été utilisées dans ce travail pour déterminer théoriquement les paramètres moléculaires et spectroscopiques des systèmes MgO, MgO+, FeC2, FeC2+ et FeC2- avec le maximum de précision possible.Dans un premier temps, nous avons étudié la molécule MgO. C’est un système de choix car, il permet de s’initier aux méthodes de calcul ab initio sur les systèmes moléculaires les plus simples (diatomiques), de tester et de comprendre ces méthodes (différentes approximations, validité, précision, …) et de bien interpréter les résultats obtenus (formation de la liaison chimique et des états moléculaires, leur symétrie, leurs couplages, leur stabilité, leur spectroscopie, …) surtout qu’il a fait l’objet de plusieurs études théoriques et expérimentales. Pour profiter de notre savoir-faire pour les molécules diatomiques nous avons étudié le système MgO+ qui a fait l’objet de notre deuxième article que sera présenté en annexe.Dans un second temps, nous avons visé les systèmes moléculaires de type FenCm afin de comprendre la croissance et la dynamique des nanotubes de carbone catalysée par le Fer. Le système diatomique FeC fait l’objet de plusieurs études théoriques et expérimentales. La plus récente est celle fourni par Demeter Tzeli… Advisors/Committee Members: Hochlaf, Majdi (thesis director).

Subjects/Keywords: Ab initio; Structure électronique; Spectroscopie; Ab initio; Electronic structure; Spectroscopy

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Maatouk, A. (2012). Étude de la croissance des nanotubes de carbone catalysée par le fer : Structures and properties of small iron-doped carbon clusters. (Doctoral Dissertation). Université Paris-Est. Retrieved from http://www.theses.fr/2012PEST1147

Chicago Manual of Style (16^th Edition):

Maatouk, Amira. “Étude de la croissance des nanotubes de carbone catalysée par le fer : Structures and properties of small iron-doped carbon clusters.” 2012. Doctoral Dissertation, Université Paris-Est. Accessed April 21, 2021. http://www.theses.fr/2012PEST1147.

MLA Handbook (7^th Edition):

Maatouk, Amira. “Étude de la croissance des nanotubes de carbone catalysée par le fer : Structures and properties of small iron-doped carbon clusters.” 2012. Web. 21 Apr 2021.

Vancouver:

Maatouk A. Étude de la croissance des nanotubes de carbone catalysée par le fer : Structures and properties of small iron-doped carbon clusters. [Internet] [Doctoral dissertation]. Université Paris-Est; 2012. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2012PEST1147.

Council of Science Editors:

Maatouk A. Étude de la croissance des nanotubes de carbone catalysée par le fer : Structures and properties of small iron-doped carbon clusters. [Doctoral Dissertation]. Université Paris-Est; 2012. Available from: http://www.theses.fr/2012PEST1147

10. Iagupov, Ilia. Numerical design of meta-materials for photovoltaic applications : Design numérique de métamatériaux pour des applications photovoltaïques.

Degree: Docteur es, Physique de la matière condensée, 2018, Université Paris-Saclay (ComUE)

URL: http://www.theses.fr/2018SACLX117

► Le but de la thèse était de simuler le spectre d'absorption de méta-matériaux pour les applications photovoltaïques. Par méta-matériaux, nous entendons une assemblée d'objets de… (more)

▼ Le but de la thèse était de simuler le spectre d'absorption de méta-matériaux pour les applications photovoltaïques. Par méta-matériaux, nous entendons une assemblée d'objets de taille nanométrique situés à distance mésoscopique. L'idée sous-jacente est qu'en modifiant la taille du nano-objet et l'arrangement géométrique, on peut ajuster le seuil d'absorption. Pour calculer ces quantités, j'ai utilisé l'état de l'art du formalisme, c'est-à-dire des méthodes ab initio.La première étape du travail a été dédiée au calcul de l'absorption d'un objet isolé (tranche de silicium, graphène, hBN). Dans le cadre de codes périodiques, on utilise une supercellule avec du vide pour isoler l'objet, et une méthode a été développée précédemment dans le groupe de Spectroscopie Théorique du LSI, pour obtenir des résultats indépendants du vide. Elle est appelée Selected-G, et a été appliquée avec succès aux surfaces de silicium. Pour une tranche isolée, une expression modifiée du potentiel coulombien dans l'espace réciproque, appelé "slab potential", doit être utilisée. Pour valider l'utilisation du potentiel de slab pour le calcul de la matrice diélectrique microscopique, j'ai simulé les spectres de perte d'énergie d'électrons pour des empilements de quelques plans de graphène, et reproduit avec succès les données expérimentales disponibles. Cela a offert la possibilité d'étudier la dispersion du plasmon d'un plan de graphène, et discuter la nature des excitations électroniques dans ce système (transitions interband ou plasmon 2D).La second étape a été consacrée à l'étude du spectre d'absorption d'une assemblée de tranches en interaction. Comme il a été mis en évidence que le formalisme de supercellule agit comme une théorie de matériau moyen avec du vide, avec l'effet erroné d'avoir des spectres dépendant de la taille de la supercellule, j'ai renversé la procédure pour extraire le spectre de la tranche en interaction, affranchi du problème du vide. La faisabilité a été démontrée sur les tranches de hBN, dont le caractère semi-conducteur à large bande interdite évite les instabilités numériques.Cela a permis de comprendre la raison pour laquelle l'absorption de la tranche en interaction de silicium apparaît à plus basse énergie que celle du matériau massif: cela vient de la présence des états de surface dans la bande interdite de la structure de bandes du massif. Néanmoins, la différence avec la tranche isolée doit être encore étudiée.La troisième partie a été dédiée à l'étude de matériaux utilisés, ou candidats, aux applications photovoltaïques comme InP et InSe. J'ai étudié dans un premier temps les structures de bandes des massifs. Pour corriger la sous-estimation de la bande interdite calculée dans l'approximation de la densité locale (LDA), j'ai calculé les corrections GW, et utilisé la fonctionnelle d'échange et corrélation de Heyd-Scuseria-Ernzerhof (HSE). Le spectre d'absorption de InP massif a été calculé en résolvant l'équation de Bethe-Salpeter, qui permet de tenir compte des effets excitoniques. Comme ce calcul est très… Advisors/Committee Members: Véniard, Valérie (thesis director).

Subjects/Keywords: Ab-initio; Métamatériaux; Photovoltaïque numérique; Ab-initio; Metamaterials; Photovoltaics; 621.312 44

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Iagupov, I. (2018). Numerical design of meta-materials for photovoltaic applications : Design numérique de métamatériaux pour des applications photovoltaïques. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2018SACLX117

Chicago Manual of Style (16^th Edition):

Iagupov, Ilia. “Numerical design of meta-materials for photovoltaic applications : Design numérique de métamatériaux pour des applications photovoltaïques.” 2018. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed April 21, 2021. http://www.theses.fr/2018SACLX117.

MLA Handbook (7^th Edition):

Iagupov, Ilia. “Numerical design of meta-materials for photovoltaic applications : Design numérique de métamatériaux pour des applications photovoltaïques.” 2018. Web. 21 Apr 2021.

Vancouver:

Iagupov I. Numerical design of meta-materials for photovoltaic applications : Design numérique de métamatériaux pour des applications photovoltaïques. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2018. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2018SACLX117.

Council of Science Editors:

Iagupov I. Numerical design of meta-materials for photovoltaic applications : Design numérique de métamatériaux pour des applications photovoltaïques. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2018. Available from: http://www.theses.fr/2018SACLX117

11. Chauvin, Sophie. Cobaltates in the high-doping regime : Insights from first-principles calculations and extended dynamical mean-field theory : Etude des cobaltates fortement dopés par calculs premiers : Principes et théorie du champ moyen dynamique étendue.

Degree: Docteur es, Physique, 2016, Université Paris-Saclay (ComUE)

URL: http://www.theses.fr/2016SACLX110

► Comme de nombreux autres oxydes de métaux de transition lamellaires, les cobaltates dopés au sodium, NaxCoO2, présentent un riche diagramme de phase. Les nombreuses instabilités… (more)

▼ Comme de nombreux autres oxydes de métaux de transition lamellaires, les cobaltates dopés au sodium, NaxCoO2, présentent un riche diagramme de phase. Les nombreuses instabilités (magnétiques, de charge) qui les caractérisent seraient notamment le fruit des corrélations électroniques. Dans cette thèse, nous nous intéressons au cas fortement dopé x=2/3 (proche de la limite de l'isolant de bande). Expérimentalement, ce composé est sujet à une disproportion de charge locale sur les atomes de cobalt, ce qui en fait un terrain d'étude privilégié pour le calcul des fonctions de corrélation de charge. Le traitement théorique de ce système est difficile a bien des égards. D'abord, la corrélation électronique demande de recourir à des approximations avancées. Ensuite, le système est sensible aux détails microscopiques, tels que transcrits dans la structure électronique réelle. Dans cette thèse, nous abordons ces deux aspects, à travers un approche sur modèle et une approche ab initio.Nous examinons d'abord l'effet des corrélations au niveau d'un modèle sur réseau triangulaire, pertinent pour les cobaltates. La compétition entre les interactions de Coulomb locale et non-locale sur un modèle de Hubbard étendu donne lieu à des fluctuations de charge, que nous traitons grâce à la théorie du champ moyen dynamique étendue. Nous dressons le diagramme de phase de notre modèle en fonction des interactions locales et non-locales. Celui-ci présente une transition du second ordre entre un état métallique homogène et une phase ordonnée de charge. Nous calculons les observables à une et deux particules dans la phase homogène, et nous déterminons l'effet des corrélations sur ces deux types d'observables. Nous interprétons ces résultats comme des conséquences du fort dopage. Nous identifions une région du diagramme de phase où la partie statique de l'interaction de Coulomb écrantée devient négative. Enfin, nous montrons comment incorporer un terme de Fock non-local à ces calculs, et nous détaillons son effet sur le diagramme de phase et sur les observables physiques.En complément de notre approche sur modèle, nous étudions les détails microscopiques du matériau réel grâce à la théorie de la fonctionnelle de la densité. Nous analysons le rôle de l'hybridation avec l’oxygène et des processus de saut électronique sur la structure de bandes pour les plans de cobalt-oxygène. Nous clarifions l'effet de certains paramètres physiques, tels que le dopage au sodium, l'arrangement cristallin ou le magnétisme, sur la structure électronique. Puis nous calculons la susceptibilité de charge selon les premiers principes, selon des approximations suggérées par notre étude de modèle sur réseau.La comparaison entre les calculs sur modèle et ab initio montre que ces approches se complètent l'une l'autre. D'une part, le modèle permet de dégager les approximations pertinentes pour le calcul des fonctions de corrélation de charge. D'autre part, les calculs ab initio et la compréhension des processus microscopiques sont le préalable à la construction d'un modèle… Advisors/Committee Members: Biermann, Silke (thesis director).

Subjects/Keywords: Corrélations; Cobaltates; Ab initio; Correlations; Cobaltates; Ab initio

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chauvin, S. (2016). Cobaltates in the high-doping regime : Insights from first-principles calculations and extended dynamical mean-field theory : Etude des cobaltates fortement dopés par calculs premiers : Principes et théorie du champ moyen dynamique étendue. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2016SACLX110

Chicago Manual of Style (16^th Edition):

Chauvin, Sophie. “Cobaltates in the high-doping regime : Insights from first-principles calculations and extended dynamical mean-field theory : Etude des cobaltates fortement dopés par calculs premiers : Principes et théorie du champ moyen dynamique étendue.” 2016. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed April 21, 2021. http://www.theses.fr/2016SACLX110.

MLA Handbook (7^th Edition):

Chauvin, Sophie. “Cobaltates in the high-doping regime : Insights from first-principles calculations and extended dynamical mean-field theory : Etude des cobaltates fortement dopés par calculs premiers : Principes et théorie du champ moyen dynamique étendue.” 2016. Web. 21 Apr 2021.

Vancouver:

Chauvin S. Cobaltates in the high-doping regime : Insights from first-principles calculations and extended dynamical mean-field theory : Etude des cobaltates fortement dopés par calculs premiers : Principes et théorie du champ moyen dynamique étendue. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2016. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2016SACLX110.

Council of Science Editors:

Chauvin S. Cobaltates in the high-doping regime : Insights from first-principles calculations and extended dynamical mean-field theory : Etude des cobaltates fortement dopés par calculs premiers : Principes et théorie du champ moyen dynamique étendue. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2016. Available from: http://www.theses.fr/2016SACLX110

Brno University of Technology

12. Pleskot, Ondřej. Prvoprincipiální studium stability krystalů pevných látek: First-principles study of stability of solid crystals.

Degree: 2018, Brno University of Technology

URL: http://hdl.handle.net/11012/33291

► This work deals with a modeling of an electronic structure of solid crystals. Specifically, densities of valence electrons, and the density of states are calculated… (more)

Subjects/Keywords: Ab initio; prvoprincipiální; VASP; Ab initio; first-principles; VASP

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APA (6^th Edition):

Pleskot, O. (2018). Prvoprincipiální studium stability krystalů pevných látek: First-principles study of stability of solid crystals. (Thesis). Brno University of Technology. Retrieved from http://hdl.handle.net/11012/33291

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Pleskot, Ondřej. “Prvoprincipiální studium stability krystalů pevných látek: First-principles study of stability of solid crystals.” 2018. Thesis, Brno University of Technology. Accessed April 21, 2021. http://hdl.handle.net/11012/33291.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Pleskot, Ondřej. “Prvoprincipiální studium stability krystalů pevných látek: First-principles study of stability of solid crystals.” 2018. Web. 21 Apr 2021.

Vancouver:

Pleskot O. Prvoprincipiální studium stability krystalů pevných látek: First-principles study of stability of solid crystals. [Internet] [Thesis]. Brno University of Technology; 2018. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/11012/33291.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Pleskot O. Prvoprincipiální studium stability krystalů pevných látek: First-principles study of stability of solid crystals. [Thesis]. Brno University of Technology; 2018. Available from: http://hdl.handle.net/11012/33291

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Ruhr Universität Bochum

13. Bialon, Arthur. The iron-boron system : ordered structures and point defects.

Degree: 2013, Ruhr Universität Bochum

URL: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-38641

► In der vorliegenden Dissertation wurde die Bildung von binären und ternären Phasen aus Übergangsmetallen und p-Block- Elementen mit Hilfe von Strukturkarten und das Eisen-Bor-System im… (more)

Subjects/Keywords: Dichtefunktionalformalismus; Ab-initio-Rechnung; Kristallstruktur; Kristallstrukturanalyse; Gitterbaufehler

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APA (6^th Edition):

Bialon, A. (2013). The iron-boron system : ordered structures and point defects. (Thesis). Ruhr Universität Bochum. Retrieved from http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-38641

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Bialon, Arthur. “The iron-boron system : ordered structures and point defects.” 2013. Thesis, Ruhr Universität Bochum. Accessed April 21, 2021. http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-38641.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Bialon, Arthur. “The iron-boron system : ordered structures and point defects.” 2013. Web. 21 Apr 2021.

Vancouver:

Bialon A. The iron-boron system : ordered structures and point defects. [Internet] [Thesis]. Ruhr Universität Bochum; 2013. [cited 2021 Apr 21]. Available from: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-38641.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Bialon A. The iron-boron system : ordered structures and point defects. [Thesis]. Ruhr Universität Bochum; 2013. Available from: http://nbn-resolving.de/urn/resolver.pl?urn=urn:nbn:de:hbz:294-38641

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Addis Ababa University

14. GETASEW, MULUALEM. AB–INITIO CALCULATIONS OF STRUCTURAL AND ELECTRONIC PROPERTIES OF A BeXZn1-XSe TERNARY ALLOY .

Degree: 2013, Addis Ababa University

URL: http://etd.aau.edu.et/dspace/handle/123456789/760

► We have used the ab-initio SIESTA code within the framework of DFT, LDA method to calculate the structural and electronic properties of BexZn1-xSe alloy for… (more)

Subjects/Keywords: ab-initio SIESTA code; DFT; LDA

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APA (6^th Edition):

GETASEW, M. (2013). AB–INITIO CALCULATIONS OF STRUCTURAL AND ELECTRONIC PROPERTIES OF A BeXZn1-XSe TERNARY ALLOY . (Thesis). Addis Ababa University. Retrieved from http://etd.aau.edu.et/dspace/handle/123456789/760

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

GETASEW, MULUALEM. “AB–INITIO CALCULATIONS OF STRUCTURAL AND ELECTRONIC PROPERTIES OF A BeXZn1-XSe TERNARY ALLOY .” 2013. Thesis, Addis Ababa University. Accessed April 21, 2021. http://etd.aau.edu.et/dspace/handle/123456789/760.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

GETASEW, MULUALEM. “AB–INITIO CALCULATIONS OF STRUCTURAL AND ELECTRONIC PROPERTIES OF A BeXZn1-XSe TERNARY ALLOY .” 2013. Web. 21 Apr 2021.

Vancouver:

GETASEW M. AB–INITIO CALCULATIONS OF STRUCTURAL AND ELECTRONIC PROPERTIES OF A BeXZn1-XSe TERNARY ALLOY . [Internet] [Thesis]. Addis Ababa University; 2013. [cited 2021 Apr 21]. Available from: http://etd.aau.edu.et/dspace/handle/123456789/760.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

GETASEW M. AB–INITIO CALCULATIONS OF STRUCTURAL AND ELECTRONIC PROPERTIES OF A BeXZn1-XSe TERNARY ALLOY . [Thesis]. Addis Ababa University; 2013. Available from: http://etd.aau.edu.et/dspace/handle/123456789/760

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Illinois – Chicago

15. Buurma, Christopher F. Application of ab-initio Methods to Grain Boundaries and Point Defects for Poly-CdTe Solar Cells.

Degree: 2015, University of Illinois – Chicago

URL: http://hdl.handle.net/10027/19477

► CdTe is a material well-suited to solar cell applications due to its 1.5 eV direct bandgap and high optical absorption. To meet energy demands, CdTe… (more)

▼ CdTe is a material well-suited to solar cell applications due to its 1.5 eV direct bandgap and high optical absorption. To meet energy demands, CdTe solar cells must be produced at a low-cost and with high throughput which often demands the use of non-ideal polycrystalline CdTe. As a result of careful process control, current thin-film poly-CdTe cells have been shown to be somewhat defect tolerant with proven industry success. Yet despite this success poly-CdTe cells are still far from their predicted Shockley-Queisser theoretical limits. The next generation cells must demonstrate higher open-circuit voltages, fill factors, and longer minority carrier lifetimes. Playing a major role in doping, defect migration, carrier recombination, and current transport are 2D extended defects both within grains and between grains as grain boundaries (GBs). A further understanding of these defects is needed which exhibit either high symmetry such as the CSL structures or those mixed or random GBs with low symmetry. Their corresponding formation and electronic behavior will be needed to develop methods to mitigate their effects and instead promote higher doping with less minority carrier recombination. Predictions and guidance on electronic and thermodynamic properties can be obtained from model atomic structures within the framework of ab-initio density-functional theory. Bulk point defect formation energies were determined for comparison to calculations of point defects along GB structures. Model atomic structures of GBs can also be created rapidly and over a wide parameter space using the Grain Boundary Genie code developed for this project. Commonly observed low-angle and special coincident grain boundaries structures were created and a subset relaxed to determine their local strain environment and interfacial energy with for comparison to STEM observations. Additionally, a series of random angle or ‘mixed’ grain boundaries were created and investigated corresponding to possible interfaces between grains that cannot be observed in STEM. Advisors/Committee Members: Sivananthan, Sivalingam (advisor), Chan, Maria K. (committee member), Grein, Christoph (committee member), Klie, Robert (committee member), Metzger, Wyatt (committee member).

Subjects/Keywords: CdTe; Solar; ab-initio; Grain Boundary

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APA (6^th Edition):

Buurma, C. F. (2015). Application of ab-initio Methods to Grain Boundaries and Point Defects for Poly-CdTe Solar Cells. (Thesis). University of Illinois – Chicago. Retrieved from http://hdl.handle.net/10027/19477

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Buurma, Christopher F. “Application of ab-initio Methods to Grain Boundaries and Point Defects for Poly-CdTe Solar Cells.” 2015. Thesis, University of Illinois – Chicago. Accessed April 21, 2021. http://hdl.handle.net/10027/19477.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Buurma, Christopher F. “Application of ab-initio Methods to Grain Boundaries and Point Defects for Poly-CdTe Solar Cells.” 2015. Web. 21 Apr 2021.

Vancouver:

Buurma CF. Application of ab-initio Methods to Grain Boundaries and Point Defects for Poly-CdTe Solar Cells. [Internet] [Thesis]. University of Illinois – Chicago; 2015. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/10027/19477.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Buurma CF. Application of ab-initio Methods to Grain Boundaries and Point Defects for Poly-CdTe Solar Cells. [Thesis]. University of Illinois – Chicago; 2015. Available from: http://hdl.handle.net/10027/19477

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Melbourne

16. Huang, Haibei. Magnetic interactions between lanthanide single molecule magnets and a magnetic substrate.

Degree: 2018, University of Melbourne

URL: http://hdl.handle.net/11343/214488

► We have theoretically and computationally investigated the magnetic interaction between the Ln III Pc 2 (Ln=Tb, Dy, Ho and Er; Pc=dianion of phthalocyanine) molecule and… (more)

▼ We have theoretically and computationally investigated the magnetic interaction between the Ln III Pc 2 (Ln=Tb, Dy, Ho and Er; Pc=dianion of phthalocyanine) molecule and a Ni(111) substrate, via the simulation of X-ray Magnetic Circular Dichroism (XMCD) experiments for two systems: LnPc2 /Ni(111) and TbPc2 /graphene/Ni(111). We have thus developed ab initio parameterized effective spin Hamiltonians having as a sole fitting parameter the magnetic coupling to the experimental magnetization of the Ni(111) substrate. Simulation of experimental data via our Hamiltonians allowed us to extract the following information about the molecule-surface coupling: (i) the Ln-Ni(111) effective coupling is antiferromagnetic; (ii) the Ln-Ni(111) strength of effective coupling decreases in the order Ln=Tb, Dy, Er; (iii) the details of the effects of magnetic anisotropy on the XMCD experimental magnetization can only be explained either by assuming a hugely anisotropic coupling mechanism, or by explicitly considering the role of a radical delocalized on two separate Pc ligands in the relevant electronic states, i.e. assuming the molecule on the surface remains close to the [LnPc2]⁰ oxidation state as before in situ ultra-high vacuum (UHV) deposition on Ni(111). Based on our simulations, it is argued that the Pc2 radical not only mediates the Ln-Ni(111) coupling, but also appears to influence the Ln-based magnetic moment observed via XMCD. While we could not achieve a clear cut identification of the signature of the Pc2 radical in the XMCD experiments, our studies indicate that the radical Pc2 ligand plays an important role in the communication between the 4f-electrons and magnetic substrates. Hence, we also performed a detailed ab initio CASSCF/RASSCF-RASSI-SO study of the intra-molecular exchange coupling between 4f-electrons and Pc2 radical ligand in [LnPc2]⁰ . We found that the overall coupling is ferromagnetic, consistent with our simulation of XMCD experiments, and especially with recent Electron Paramagnetic Resonance (EPR) results, although the ferromagnetic coupling is greatly overestimated at the CASSCF level of theory; We also found that a more accurate predictions of this ferromagnetic coupling can be achieved if accounting for spin-polarization effects via extended active spaces at the RASSCF level of theory.

Subjects/Keywords: lanthanides; single molecule magnets; ab-initio

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APA (6^th Edition):

Huang, H. (2018). Magnetic interactions between lanthanide single molecule magnets and a magnetic substrate. (Doctoral Dissertation). University of Melbourne. Retrieved from http://hdl.handle.net/11343/214488

Chicago Manual of Style (16^th Edition):

Huang, Haibei. “Magnetic interactions between lanthanide single molecule magnets and a magnetic substrate.” 2018. Doctoral Dissertation, University of Melbourne. Accessed April 21, 2021. http://hdl.handle.net/11343/214488.

MLA Handbook (7^th Edition):

Huang, Haibei. “Magnetic interactions between lanthanide single molecule magnets and a magnetic substrate.” 2018. Web. 21 Apr 2021.

Vancouver:

Huang H. Magnetic interactions between lanthanide single molecule magnets and a magnetic substrate. [Internet] [Doctoral dissertation]. University of Melbourne; 2018. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/11343/214488.

Council of Science Editors:

Huang H. Magnetic interactions between lanthanide single molecule magnets and a magnetic substrate. [Doctoral Dissertation]. University of Melbourne; 2018. Available from: http://hdl.handle.net/11343/214488

Georgia Tech

17. Plaisance, Brandon P. First principles approach to identification of potential ferroelectric and multiferroic molecular materials.

Degree: MS, Chemical and Biomolecular Engineering, 2016, Georgia Tech

URL: http://hdl.handle.net/1853/55039

► Flexible electronics have garnered much interest over the past several decades. Hybrid organic-inorganic materials, such as metal-organic frameworks, offer a unique opportunity to encompass the… (more)

Subjects/Keywords: Ferroelectricity; Multiferroicity; Metal-organic frameworks; Ab initio

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APA (6^th Edition):

Plaisance, B. P. (2016). First principles approach to identification of potential ferroelectric and multiferroic molecular materials. (Masters Thesis). Georgia Tech. Retrieved from http://hdl.handle.net/1853/55039

Chicago Manual of Style (16^th Edition):

Plaisance, Brandon P. “First principles approach to identification of potential ferroelectric and multiferroic molecular materials.” 2016. Masters Thesis, Georgia Tech. Accessed April 21, 2021. http://hdl.handle.net/1853/55039.

MLA Handbook (7^th Edition):

Plaisance, Brandon P. “First principles approach to identification of potential ferroelectric and multiferroic molecular materials.” 2016. Web. 21 Apr 2021.

Vancouver:

Plaisance BP. First principles approach to identification of potential ferroelectric and multiferroic molecular materials. [Internet] [Masters thesis]. Georgia Tech; 2016. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/1853/55039.

Council of Science Editors:

Plaisance BP. First principles approach to identification of potential ferroelectric and multiferroic molecular materials. [Masters Thesis]. Georgia Tech; 2016. Available from: http://hdl.handle.net/1853/55039

University of Tennessee – Knoxville

18. Li, Congyi. Characterization of Radiation Effects and Ab Initio Modeling of Defects in a High Entropy Alloy for Nuclear Power Application.

Degree: 2018, University of Tennessee – Knoxville

URL: https://trace.tennessee.edu/utk_graddiss/5005

► A novel Co-free NiFeMnCr HEA was synthesized for both ion and neutron irradiation studies. 3 and 5.8MeV heavy ion irradiations were conducted at room temperature… (more)

▼ A novel Co-free NiFeMnCr HEA was synthesized for both ion and neutron irradiation studies. 3 and 5.8MeV heavy ion irradiations were conducted at room temperature and 400 – 700 °C from 0.03 to 10dpa. Post-irradiation examination included x-ray diffraction, nanoindentation hardness and transmission electron microscopy. The HEA exhibited quantitatively superior radiation resistance than conventional alloys, including suppressed void swelling and solute segregation.Neutron irradiation was conducted at 60 °C from 0.1 to 1dpa. Microhardness, electrical resistivity and positron annihilation spectroscopy measurements were performed at room temperature before and after isochronal annealing up to 700°C on the neutron-irradiated samples. The HEA retains fundamental stability after neutron irradiation. Compared with metals and conventional alloys, the HEA showed similar annealing trend of hardness and vacancy-type of defects. On the other hand, this HEA showed unique annealing trend of electrical resistivity. The large radiation induced resistivity increase (>10 μΩ∙cm) did not recover up to 700 °C, suggesting short range ordering phenomena may be critical in radiation effects of HEA.In parallel, ab initio modeling was conducted to establish a solid foundation for multiscale modeling of HEA as well as to reveal unique defect physics of HEA. Magnetic structure was computed based on coherent potential. Vacancy energetics were computed by Vienna Ab initio Simulation Package (VASP). Modeling results shows that it is reasonable to neglect magnetic interactions. The statistical distribution of vacancy formation energy is weakly dependent upon either the chemical species of the atom site associated with the vacancy, or local chemical environment. The calculated migration energy values show a large spread, varying between 0.55 to 1.68eV, although the mean value is comparable to that of conventional austenitic alloys. Finally, positron lifetime of bulk HEA, mono-vacancy and small vacancy clusters were computed by a finite element based ab initio package to facilitate the interpretation of experimental results from positron annihilation spectroscopy.

Subjects/Keywords: Radiation Effect; Alloy; Ab initio Modeling

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APA (6^th Edition):

Li, C. (2018). Characterization of Radiation Effects and Ab Initio Modeling of Defects in a High Entropy Alloy for Nuclear Power Application. (Doctoral Dissertation). University of Tennessee – Knoxville. Retrieved from https://trace.tennessee.edu/utk_graddiss/5005

Chicago Manual of Style (16^th Edition):

Li, Congyi. “Characterization of Radiation Effects and Ab Initio Modeling of Defects in a High Entropy Alloy for Nuclear Power Application.” 2018. Doctoral Dissertation, University of Tennessee – Knoxville. Accessed April 21, 2021. https://trace.tennessee.edu/utk_graddiss/5005.

MLA Handbook (7^th Edition):

Li, Congyi. “Characterization of Radiation Effects and Ab Initio Modeling of Defects in a High Entropy Alloy for Nuclear Power Application.” 2018. Web. 21 Apr 2021.

Vancouver:

Li C. Characterization of Radiation Effects and Ab Initio Modeling of Defects in a High Entropy Alloy for Nuclear Power Application. [Internet] [Doctoral dissertation]. University of Tennessee – Knoxville; 2018. [cited 2021 Apr 21]. Available from: https://trace.tennessee.edu/utk_graddiss/5005.

Council of Science Editors:

Li C. Characterization of Radiation Effects and Ab Initio Modeling of Defects in a High Entropy Alloy for Nuclear Power Application. [Doctoral Dissertation]. University of Tennessee – Knoxville; 2018. Available from: https://trace.tennessee.edu/utk_graddiss/5005

19. Azarias, Cloé. Modeling azacalixphyrin macrocycles : Modélisation de macrocycles de la famille des azacalixphyrines.

Degree: Docteur es, Chimie théorique, physique, analytique, 2018, Nantes

URL: http://www.theses.fr/2018NANT4021

►

Cette thèse porte sur la modélisation des propriétés structurales, aromatiques et spectroscopiques d'une nouvelle classe de macrocycles alternatifs aux porphyrines, les azacalixphyrines (ACPs). Ces macrocycles… (more)

▼

Cette thèse porte sur la modélisation des propriétés structurales, aromatiques et spectroscopiques d'une nouvelle classe de macrocycles alternatifs aux porphyrines, les azacalixphyrines (ACPs). Ces macrocycles conjugués, synthétisés et caractérisés pour la première fois en 2010 par le groupe d’Olivier Siri à Marseille, ont montré des propriétés exceptionnelles (structure, absorption, tautomérie, et complexation). Cette thèse vise à proposer de nouveaux dérivés aux propriétés améliorées, notamment en ce qui concerne leur absorption, en utilisant les outils offerts par la chimie théorique. Parmi toutes les approches ab initio permettant de modéliser les ACPs, la théorie fonctionnelle de la densité (DFT) et sa forme dépendante du temps (TDDFT) ont été principalement appliquées, bien que des calculs utilisant des méthodes alternatives aient également été effectués, notamment à l'aide du formalisme Bethe-Salpeter (BSE/evGW) dans le cadre d'une collaboration avec l'équipe du Dr. Xavier Blase à Grenoble. Trois stratégies chimiques ont été évaluées: (i) l’extension de la délocalisation des électrons  en fusionnant plusieurs unités ACP; (ii) la substitution de l’ACP via l'addition de groupes électroactifs; et (iii) le couplage du macrocycle avec un fluorophore présentant une absorption complémentaire afin d'absorber la lumière sur une plus grande gamme du spectre et déclencher des processus de transfert d'énergie entre les sous-unités. Les deux premiers axes ont été réalisés en collaboration avec l'équipe d’Olivier Siri alors que le dernier est le fruit d'une collaboration avec le groupe de Benedetta Mennucci à Pise.

This thesis focuses on the modeling of the structural, aromatic, and spectroscopic properties of a new class of macrocycles alternative to porphyrins, i.e., azacalixphyrins (ACPs). These conjugated macrocycles have first been synthesized and characterized in 2010 by Siri’s group in Marseille and revealed exceptional features (structure, NIR absorption, tautomerism, and complexation). This thesis aimed at using ab initio methods to propose new ACP derivatives with improved properties with a focus on their absorption. The Density Functional Theory (DFT) and Time- Dependent DFT (TD-DFT) methods have been predominantly applied, although alternative wavefunction-based theories [the second-order Coupled-Cluster, CC2, and the Algebraic Diagrammatic Construction, ADC(2)] as well as the Bethe-Salpeter formalism, BSE/evGW, have also been used. Three major directions to develop new ACP derivatives have been investigated: (i) the extension of the ACP -conjugation path by fusing several ACP moieties leading to multimers; (ii) chemical modifications of the ACP unit by addition of electroactive groups; and (iii) coupling of the ACP moiety with a fluorophore presenting a complementary absorption spectrum in order to improve the light harvesting and to trigger excitation energy transfer processes. The two former axes have been investigated in collaboration with Siri’s team whereas the latter has arisen from a collaboration…

Advisors/Committee Members: Jacquemin, Denis (thesis director), Lasorne, Benjamin (thesis director).

Subjects/Keywords: Calculs ab initio; Azacalixphyrine; TD-DFT; DFT

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APA (6^th Edition):

Azarias, C. (2018). Modeling azacalixphyrin macrocycles : Modélisation de macrocycles de la famille des azacalixphyrines. (Doctoral Dissertation). Nantes. Retrieved from http://www.theses.fr/2018NANT4021

Chicago Manual of Style (16^th Edition):

Azarias, Cloé. “Modeling azacalixphyrin macrocycles : Modélisation de macrocycles de la famille des azacalixphyrines.” 2018. Doctoral Dissertation, Nantes. Accessed April 21, 2021. http://www.theses.fr/2018NANT4021.

MLA Handbook (7^th Edition):

Azarias, Cloé. “Modeling azacalixphyrin macrocycles : Modélisation de macrocycles de la famille des azacalixphyrines.” 2018. Web. 21 Apr 2021.

Vancouver:

Azarias C. Modeling azacalixphyrin macrocycles : Modélisation de macrocycles de la famille des azacalixphyrines. [Internet] [Doctoral dissertation]. Nantes; 2018. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2018NANT4021.

Council of Science Editors:

Azarias C. Modeling azacalixphyrin macrocycles : Modélisation de macrocycles de la famille des azacalixphyrines. [Doctoral Dissertation]. Nantes; 2018. Available from: http://www.theses.fr/2018NANT4021

Colorado School of Mines

20. LaCount, Michael D. Energy pooling upconversion in free space and optical cavities.

Degree: PhD, Physics, 2017, Colorado School of Mines

URL: http://hdl.handle.net/11124/170985

► The ability to efficiently convert the wavelength of light has value in a wide range of disciplines that include the fields of photovoltaics, plant growth,… (more)

▼ The ability to efficiently convert the wavelength of light has value in a wide range of disciplines that include the fields of photovoltaics, plant growth, optics and medicine. The processes by which such transformations are carried out are known as upconversions and downconversions. There are several ways to up/down convert light, each with its own attributes, issues, and competing mechanisms. Most are associated with one-body or two-body processes. Three-body dynamics are also possible though, going by the names of quantum cutting (downconversion) and energy pooling (upconversion). These use virtual excited electronic states to mediate conversions as has been experimentally realized using lanthanide ions embedded in wide bandgap materials. The use of lanthanides to convert light is not ideal due to their relative scarcity, toxicity, and the limited range of light frequencies that can be absorbed and emitted. Organic molecules, on the other hand, are typically non-toxic, are made up of abundant elements, and can be designed with tailored spectral properties. At issue is whether or not they can be used to carry out efficient energy pooling, the central question to be answered in this thesis. The research presented here draws on a perturbative quantum electrodynamics framework previously established for generic energy pooling. It was used to develop a computational methodology for determining the rate of energy pooling and its competing processes. This, in turn, draws on a combination of time-dependent density functional theory, quantum electrodynamics, and perturbation theory to generate the requisite material property data. This computational model was applied to two test systems consisting of stilbene-fluorescein and hexabenzocoronene-oligothiophene. The stilbene-fluorescein system was found to have a maximum energy pooling rate efficiency (as compared to competing processes) of 17% and the hexabenzocoronene-oligothiophene system was found to have a maximum energy pooling rate efficiency of 99%. This demonstrates that the energy pooling rate can be made faster than its competing processes. Based on the results of this study, a set of design rules was developed to optimize the rate efficiency of energy pooling. Prior to this research, no attempt had been made to determine if energy pooling could be made to out-pace competing processes – i.e. whether or not a molecular system could be designed to utilize energy pooling as an efficient means of upconversion. This initial investigation was part of a larger effort involving a team of researchers at the University of Colorado, Boulder and at the National Renewable Energy Laboratory. After establishing our computational proof-of-concept, we collectively used the new design rules to select an improved system for energy pooling. This consisted of rhodamine 6G and stilbene-420. These molecules were fabricated into a thin film, and the maximum internal quantum yield was measured to be 36% under sufficiently high intensity light. To further increase the efficiency of energy… Advisors/Committee Members: Lusk, Mark T. (advisor), Carr, Lincoln D. (committee member), Durfee, Charles G. (committee member), Sellinger, Alan (committee member).

Subjects/Keywords: cavity; perturbation; upconversion; kinetic; Ab initio; QED

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APA (6^th Edition):

LaCount, M. D. (2017). Energy pooling upconversion in free space and optical cavities. (Doctoral Dissertation). Colorado School of Mines. Retrieved from http://hdl.handle.net/11124/170985

Chicago Manual of Style (16^th Edition):

LaCount, Michael D. “Energy pooling upconversion in free space and optical cavities.” 2017. Doctoral Dissertation, Colorado School of Mines. Accessed April 21, 2021. http://hdl.handle.net/11124/170985.

MLA Handbook (7^th Edition):

LaCount, Michael D. “Energy pooling upconversion in free space and optical cavities.” 2017. Web. 21 Apr 2021.

Vancouver:

LaCount MD. Energy pooling upconversion in free space and optical cavities. [Internet] [Doctoral dissertation]. Colorado School of Mines; 2017. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/11124/170985.

Council of Science Editors:

LaCount MD. Energy pooling upconversion in free space and optical cavities. [Doctoral Dissertation]. Colorado School of Mines; 2017. Available from: http://hdl.handle.net/11124/170985

21. COURA, D. V. B. Estudo ab initio do sistema molecular HCO de interesse atmosférico.

Degree: 2018, Universidade Federal do Espírito Santo; Mestrado em Física; Programa de Pós-Graduação em Física; UFES; BR

URL: http://repositorio.ufes.br/handle/10/7371

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Made available in DSpace on 2018-08-01T21:59:24Z (GMT). No. of bitstreams: 1 tese_11854_Dissertação Final Daniel Vitor B. Coura - PPGFis.pdf: 1279828 bytes, checksum: 3fc2081f8caf4a6f36fb23b02e664244 (MD5) Previous… (more)

Subjects/Keywords: Interação molecular; Cálculos ab initio; Molécula HCO

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APA (6^th Edition):

COURA, D. V. B. (2018). Estudo ab initio do sistema molecular HCO de interesse atmosférico. (Masters Thesis). Universidade Federal do Espírito Santo; Mestrado em Física; Programa de Pós-Graduação em Física; UFES; BR. Retrieved from http://repositorio.ufes.br/handle/10/7371

Chicago Manual of Style (16^th Edition):

COURA, D V B. “Estudo ab initio do sistema molecular HCO de interesse atmosférico.” 2018. Masters Thesis, Universidade Federal do Espírito Santo; Mestrado em Física; Programa de Pós-Graduação em Física; UFES; BR. Accessed April 21, 2021. http://repositorio.ufes.br/handle/10/7371.

MLA Handbook (7^th Edition):

COURA, D V B. “Estudo ab initio do sistema molecular HCO de interesse atmosférico.” 2018. Web. 21 Apr 2021.

Vancouver:

COURA DVB. Estudo ab initio do sistema molecular HCO de interesse atmosférico. [Internet] [Masters thesis]. Universidade Federal do Espírito Santo; Mestrado em Física; Programa de Pós-Graduação em Física; UFES; BR; 2018. [cited 2021 Apr 21]. Available from: http://repositorio.ufes.br/handle/10/7371.

Council of Science Editors:

COURA DVB. Estudo ab initio do sistema molecular HCO de interesse atmosférico. [Masters Thesis]. Universidade Federal do Espírito Santo; Mestrado em Física; Programa de Pós-Graduação em Física; UFES; BR; 2018. Available from: http://repositorio.ufes.br/handle/10/7371

Johannes Gutenberg Universität Mainz

22. Wendler, Katharina. Ionic liquids in a multiscale study.

Degree: 2012, Johannes Gutenberg Universität Mainz

URL: http://ubm.opus.hbz-nrw.de/volltexte/2012/3075/

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Trotz des hohen Interesse an Ionischen Flüssigkeiten wird das zielgerichtete Design und die Anwendung Ionischer Flüssigkeiten durch fehlendes grundlegendes Verständnis erschwert. Deshalb wurde die Balance… (more)

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Trotz des hohen Interesse an Ionischen Flüssigkeiten wird das zielgerichtete Design und die Anwendung Ionischer Flüssigkeiten durch fehlendes grundlegendes Verständnis erschwert. Deshalb wurde die Balance der molekularen Wechselwirkungen in Ionischen Flüssigkeiten studiert, um die Eigenschaften dieser zu verstehen und die Kraftfeldentwicklung im Rahmen des Multiskalenansatzes zu systematisieren. Es wurden reine Imidazolium-basierte Ionische Flüssigkeiten, Mischungen mit kleinen Molekülen und eine protische Ionische Flüssigkeit mit ab-initio-Methoden, hauptsächlich Car-Parrinello-Molekulardynamik, untersucht. Weiterhin wurden Eigenschaften der Flüssigphase mit denen von Ionenpaaren verglichen.rnIm Fokus standen die molekularen elektrostatischen Eigenschaften und es wurde gezeigt, dass Coulomb-Wechselwirkungen zu einzigartigen Charakteristika führten. So waren die Ionen-Nettoladungen stets reduziert, die molekularen Dipolmomentverteilungen sehr breit, elektronische Polarisation war entscheidend. Die elektrostatischen Eigenschaften waren allgemein lokal auf molekularen Größen- und Zeitskalen und hingen stark von Phasenzustand und Zusammensetzung ab. Für andere molekulare Eigenschaften, wie der Neigung zu dispersiven Kontakten oder Wasserstoffbrücken, wurde gezeigt, dass sie einen entscheidenden Einfluss auf die Feinstruktur Ionischer Flüssigkeiten hatten. Das Gleichgewicht der Wechselwirkungen zeigte sich auch in Leistungsspektren, die sich aus den ab-initio-Molekulardynamiksimulationen ergaben. Diese boten einen neuen Weg für den Vergleich zum Experiment und für einen Einblick in die schnelle Dynamik Ionischer Flüssigkeiten.

Despite the overwhelming interest in ionic liquids, rational design and applications are hindered by a lack of fundamental understanding. Hence, the balance of molecular interactions in ionic liquids was characterized within the multiscale approach. Therefore, several neat imidazolium ionic liquids, mixtures with small solutes, and a protic ionic liquid were studied by ab initio methods, mainly Car-Parrinello molecular dynamics. Furthermore, liquid phase properties were compared to those of ion pairs.rnSpecial focus was on the molecular electrostatic properties and it emerged that the Coulomb interaction led to unique characteristics: The ion net charges were found to be reduced, the molecular dipole moment distributions were very broad, electronic polarization was decisive. The electrostatic properties were demonstrated to be local on molecular size and time scales and highly sensitive to the phase state and its composition. The chemical specificity, the likeliness of dispersive contacts or hydrogen bonds, was shown to have a crucial influence on the liquids' fine structures. The interactions' balance was also studied by power spectra based on the ab initio molecular dynamics simulations. These were demonstrated to offer a new way for comparison to experiment and an insight into the fast dynamics.

Subjects/Keywords: Ionische Fluessigkeiten, ab-initio-Molekulardynamik; ionic liquids, ab-initio molecular dynamics; Chemistry and allied sciences

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Wendler, K. (2012). Ionic liquids in a multiscale study. (Doctoral Dissertation). Johannes Gutenberg Universität Mainz. Retrieved from http://ubm.opus.hbz-nrw.de/volltexte/2012/3075/

Chicago Manual of Style (16^th Edition):

Wendler, Katharina. “Ionic liquids in a multiscale study.” 2012. Doctoral Dissertation, Johannes Gutenberg Universität Mainz. Accessed April 21, 2021. http://ubm.opus.hbz-nrw.de/volltexte/2012/3075/.

MLA Handbook (7^th Edition):

Wendler, Katharina. “Ionic liquids in a multiscale study.” 2012. Web. 21 Apr 2021.

Vancouver:

Wendler K. Ionic liquids in a multiscale study. [Internet] [Doctoral dissertation]. Johannes Gutenberg Universität Mainz; 2012. [cited 2021 Apr 21]. Available from: http://ubm.opus.hbz-nrw.de/volltexte/2012/3075/.

Council of Science Editors:

Wendler K. Ionic liquids in a multiscale study. [Doctoral Dissertation]. Johannes Gutenberg Universität Mainz; 2012. Available from: http://ubm.opus.hbz-nrw.de/volltexte/2012/3075/

23. Chen, Si. Influence de l'orientation des grains de ferrite sur l'oxydation sélective de l'acier : Influence of ferrite grain orientation on selective oxidation of steel.

Degree: Docteur es, Sciences des matériaux, 2012, Châtenay-Malabry, Ecole centrale de Paris

URL: http://www.theses.fr/2012ECAP0018

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Le procédé de galvanisation en continu consiste à recouvrir les tôles d’aciers d’un revêtement de zinc en les immergeant dans un bain métallique fondu. Lors… (more)

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Le procédé de galvanisation en continu consiste à recouvrir les tôles d’aciers d’un revêtement de zinc en les immergeant dans un bain métallique fondu. Lors du recuit continu à 800°C sous atmosphère N2‐H2 qui précède l’immersion de la tôle dans le bain, la structure de l’acier est recristallisée et les oxydes de fer sont réduits. Il se produit en même temps la ségrégation et l’oxydation des éléments d’alliages moins nobles que le fer, les oxydes formés pouvant être à l’origine de défauts de revêtement. Afin de mieux comprendre les réactions d’oxydation sélective qui se produisent à la surface et en profondeur de l’acier, nous avons étudié la germination et la croissance d’oxydes sélectifs sur un acier ferritique. Des alliages binaires de FeMn ont été étudiés dans ce travail. Les particules d'oxyde sont composées de l'oxyde de manganèse MnO. L'oxydation externe dépend de l'orientation cristallographique du substrat. Des particules de différentes formes sont observées sur des grains de ferrite d'orientations différentes : des particules cubiques se trouvent sur la surface (100), des particules triangulaires sur la surface (110) et des particules hexagonales sur la surface (111). Une étude théorique plus approfondie a été réalisée à l'aide de simulation numérique par la méthode DFT et le code SIESTA. Aucune influence significative de la présence de manganèse n’a été trouvée sur l'énergie d'adsorption dissociative du dioxygène à l'échelle atomique. Cependant, la barrière de diffusion des atomes de Fe, Mn, et O est beaucoup plus faible sur la surface (110) que sur la surface (001). Ceci peut être une explication de la raison pour laquelle la taille des particules est plus grande sur la surface (110) que sur la surface (100).

Continuous galvanizing process involving immersion in a molten zinc bath is commonly used to form zinc coatings on steel sheets. Before hot‐dip galvanizing, the steel sheets are annealed at a temperature of 800°C in a N2 atmosphere containing 5 vol.% of H2, with only traces of water. This heat treatment is used to recrystallize the steel substrate and to reduce the iron oxides in order to improve the wettability by liquid zinc. At the same time, the less‐noble alloying elements of the steel preferentially oxidize and diffuse towards the surface. The aim of this study is a better understanding of selective oxidation of ferritic steels. The binary alloys of FeMn are studied in this work. The oxide particles are found to be composed of manganese oxide MnO. External oxidation is found to be dependent on the crystallographic orientation of the substrate. Particles of different shapes are observed on ferrite grains of different orientations: square particles are found on the (100) surface, triangle particles on the (110) surface and hexagon particles are found on the (111) surface. Further theoretical study was carried out using numerical simulation with DFT method and SIESTA code. No significant influence of manganese presence has been found on the dissociative adsorption energy of dioxygen at the…

Advisors/Committee Members: Guillot, Jean-Bernard (thesis director).

Subjects/Keywords: Recuit continu; Oxydation sélective; Calcul ab initio; Continuous annealing; Selective oxidation; Ab initio calculation

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Chen, S. (2012). Influence de l'orientation des grains de ferrite sur l'oxydation sélective de l'acier : Influence of ferrite grain orientation on selective oxidation of steel. (Doctoral Dissertation). Châtenay-Malabry, Ecole centrale de Paris. Retrieved from http://www.theses.fr/2012ECAP0018

Chicago Manual of Style (16^th Edition):

Chen, Si. “Influence de l'orientation des grains de ferrite sur l'oxydation sélective de l'acier : Influence of ferrite grain orientation on selective oxidation of steel.” 2012. Doctoral Dissertation, Châtenay-Malabry, Ecole centrale de Paris. Accessed April 21, 2021. http://www.theses.fr/2012ECAP0018.

MLA Handbook (7^th Edition):

Chen, Si. “Influence de l'orientation des grains de ferrite sur l'oxydation sélective de l'acier : Influence of ferrite grain orientation on selective oxidation of steel.” 2012. Web. 21 Apr 2021.

Vancouver:

Chen S. Influence de l'orientation des grains de ferrite sur l'oxydation sélective de l'acier : Influence of ferrite grain orientation on selective oxidation of steel. [Internet] [Doctoral dissertation]. Châtenay-Malabry, Ecole centrale de Paris; 2012. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2012ECAP0018.

Council of Science Editors:

Chen S. Influence de l'orientation des grains de ferrite sur l'oxydation sélective de l'acier : Influence of ferrite grain orientation on selective oxidation of steel. [Doctoral Dissertation]. Châtenay-Malabry, Ecole centrale de Paris; 2012. Available from: http://www.theses.fr/2012ECAP0018

24. Bruna Luana Marcial. Estudo da estrutura e reatividade de híbridos moleculares de platina(II) com potencial antitumoral.

Degree: 2009, Universidade Federal de Juiz de Fora

URL: http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=612

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In this work, theoretical methods were applied to evaluate the structural, thermodynamic and kinetic properties of compounds analog to cisplatin, named molecular hybrids, because they… (more)

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In this work, theoretical methods were applied to evaluate the structural, thermodynamic and kinetic properties of compounds analog to cisplatin, named molecular hybrids, because they present a platinum metal center linked to a molecule of the tetracycline family. All the properties were calculated using the Density Functional Theory (DFT) in gas phase and aqueous phase. Firstly, it was analyzed the reactivity of the monoaquo complex AHTC-Pt(II) with different nucleophiles of biological importance, the DNA bases (Guanine and Adenine) and the aminoacids (Cysteine and Metionine). These reactions followed the standard mechanism of the cisplatin in biological medium, and therefore, the results obtained for the AHTC-Pt(II) complex were compared with literature data for cisplatin, showing that these reactions have similar rates, suggesting that the AHTC-Pt(II) complex may be a potential analog to cisplatin as an antitumor drug. The thermodynamic of the formation of a new platinum complex (II) with the chemically modified tetracycline (CMT-3) was studied. According to experimental observations for the tetracycline analog, we investigated the Pt(II) coordination with CMT-3 molecule, having been proposed 18 distinct coordination sites, considering all ionized forms for the free ligand, called LH2, LH- and L2-. As a result, the 13C NMR and the UV/Vis spectra for the ligand and the complexes were calculated. The most stable coordination modes are in the ring A, being the site O12-O1 (ligand LH2) and O3-Oam (ligand LH- and 2-) the most favorable. We believe that the analysis presented in this work can be useful for experimentalists at the assignment of complexation mode for Pt(II) (and other metals) with CMT-3 and other chemically modified tetracycline. We believe that in general, the results obtained in this work show the importance of computational chemistry as auxiliary technique for determination of structure and reactivity of complex systems

Neste trabalho, foram utilizadas metodologias teóricas para avaliar propriedades estruturais, termodinâmicas e cinéticas de compostos análogos da cisplatina, considerados híbridos moleculares, por apresentarem um centro metálico de platina(II) e um ligante da família das tetraciclinas. Todas as propriedades foram calculadas em fase gasosa e em solução aquosa usando Teoria do Funcional da Densidade (DFT). Primeiramente foi avaliado a reatividade do complexo AHTC-Pt(II) monoáquo com diferentes nucleófilos de importância biológica, as bases nitrogenadas representativas do DNA (Guanina e Adenina) e os aminoácidos (Cisteína e Metionina). Essas reações seguem o mecanismo padrão da cisplatina no meio biológico, portanto, foram comparados os resultados obtidos para o complexo AHTC-Pt(II) com dados da literatura para cisplatina, mostrando que as reações possuem velocidades similares, sugerindo que o complexo AHTC-Pt(II) pode representar um potencial análogo da cisplatina enquanto atitumoral. Foram estudados também a termodinâmica de formação de um novo complexo de platina(II), tendo como…

Advisors/Committee Members: Hélio Ferreira dos Santos, Wagner Batista de Almeida, Geórgia Maria Amaral Junqueira.

Subjects/Keywords: Tetraciclina; Platina(II); QUIMICA; Cálculos ab initio; Platinum(II); Tetracycline; Ab initio calculations

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APA (6^th Edition):

Marcial, B. L. (2009). Estudo da estrutura e reatividade de híbridos moleculares de platina(II) com potencial antitumoral. (Thesis). Universidade Federal de Juiz de Fora. Retrieved from http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=612

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Marcial, Bruna Luana. “Estudo da estrutura e reatividade de híbridos moleculares de platina(II) com potencial antitumoral.” 2009. Thesis, Universidade Federal de Juiz de Fora. Accessed April 21, 2021. http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=612.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Marcial, Bruna Luana. “Estudo da estrutura e reatividade de híbridos moleculares de platina(II) com potencial antitumoral.” 2009. Web. 21 Apr 2021.

Vancouver:

Marcial BL. Estudo da estrutura e reatividade de híbridos moleculares de platina(II) com potencial antitumoral. [Internet] [Thesis]. Universidade Federal de Juiz de Fora; 2009. [cited 2021 Apr 21]. Available from: http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=612.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Marcial BL. Estudo da estrutura e reatividade de híbridos moleculares de platina(II) com potencial antitumoral. [Thesis]. Universidade Federal de Juiz de Fora; 2009. Available from: http://www.bdtd.ufjf.br/tde_busca/arquivo.php?codArquivo=612

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

25. Brites, Vincent. Détermination ab initio de potentiels électroniques pour le calcul de données spectroscopiques : Ab Initio Determination of Electronic Potentials for Spectroscopic Datas Computation.

Degree: Docteur es, Chimie, 2010, Université Paris-Est

URL: http://www.theses.fr/2010PEST1052

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La structure et la spectroscopie de molécules d'intérêt astrophysique ont été étudiées par des méthodes de calcul électronique ab initio hautement corrélées. Notre démarche a… (more)

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La structure et la spectroscopie de molécules d'intérêt astrophysique ont été étudiées par des méthodes de calcul électronique ab initio hautement corrélées. Notre démarche a tout d'abord été d'étudier des systèmes allant de deux à quatre atomes, afin de voir l'influence du niveau de calcul électronique utilisé lors de la détermination de données comparables aux résultats expérimentaux. Ainsi, l'étude de la spectroscopie des états électroniques de la molécule AlCl a été entreprise. Les résultats obtenus pour ce système reproduisent parfaitement les mesures expérimentales existantes tout en introduisant la compréhension des phénomènes observés. Nous avons ensuite prédit un ensemble de données pour les ions AlCl+ et AlCl2+, en utilisant la même méthodologie. Nous avons également entrepris des calculs de durée de vie de prédissociation pour les molécules SH et SH+. Nos courbes d'énergie potentielle hautement corrélée nous ont permis de reproduire avec une grande précision les durées de vie de prédissociation des niveaux rovibrationnels de SH. Par la suite, nous avons étudié une molécule d'intérêt astrophysique, détectée dans l'atmosphère de Titan, N2H+. Nous avons généré des surfaces d'énergie potentielle multidimensionnelles pour les états fondamentaux des molécules N2H+, N2H2+ et N2HAr+. Ces surfaces ont été utilisées pour le calcul des niveaux rovibrationnels de ces ions et de leurs espèces deutérées. Un excellent accord avec les donné es expérimentales disponibles a été obtenu, et un ensemble de constantes spectroscopiques a été prédit. Enfin, nous nous sommes intéressés à une molécule plus grande, Si(C2H3)4. Cette étude nous a permis d'établir une méthodologie pour le calcul de la structure et des états électroniques excités de molécules de taille moyenne. Nous avons également effectué des calculs sur l'ion Si(C2H3)4+, afin d'interpréter sa fragmentation mesurée lors de l'expérience d'impact d'électron réalisée à l'Université de Bratislava durant cette thèse

Highly correlated ab initio methodologies were used to investigate the structure and the spectroscopy of small and medium sized molecules at different levels of theory. Our results are compared to the available experimental data. For the AlCl molecule, our computed spectroscopic constants were in good agreement with the experimental ones, allowing us to predict a set of predictive data for the less known AlCl+ and AlCl2+ ions. After that, we treated the predissociation lifetimes of the A state of SH and SH+. Our highly correlated calculations allowed us to reproduce the lifetimes measured experimentally. Thereafter, multidimensional potential energy surfaces of the ground state of N2H+, N2H2+ and N2HAr+ were generated. These surfaces were used for the calculations of rovibrational levels of these ions and their respective deuterated species. An overall excellent agreement was obtained comparing to the available experimental measurements. Finall y, we investigated the Si(C2H3)4 molecule in order to establish a methodology for the treatment of the structure…

Advisors/Committee Members: Hochlaf, Majdi (thesis director).

Subjects/Keywords: Calculs ab initio; Spectroscopie théorique; États excités; Ab initio calculations; Theoretical spectroscopy; Excited states

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Brites, V. (2010). Détermination ab initio de potentiels électroniques pour le calcul de données spectroscopiques : Ab Initio Determination of Electronic Potentials for Spectroscopic Datas Computation. (Doctoral Dissertation). Université Paris-Est. Retrieved from http://www.theses.fr/2010PEST1052

Chicago Manual of Style (16^th Edition):

Brites, Vincent. “Détermination ab initio de potentiels électroniques pour le calcul de données spectroscopiques : Ab Initio Determination of Electronic Potentials for Spectroscopic Datas Computation.” 2010. Doctoral Dissertation, Université Paris-Est. Accessed April 21, 2021. http://www.theses.fr/2010PEST1052.

MLA Handbook (7^th Edition):

Brites, Vincent. “Détermination ab initio de potentiels électroniques pour le calcul de données spectroscopiques : Ab Initio Determination of Electronic Potentials for Spectroscopic Datas Computation.” 2010. Web. 21 Apr 2021.

Vancouver:

Brites V. Détermination ab initio de potentiels électroniques pour le calcul de données spectroscopiques : Ab Initio Determination of Electronic Potentials for Spectroscopic Datas Computation. [Internet] [Doctoral dissertation]. Université Paris-Est; 2010. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2010PEST1052.

Council of Science Editors:

Brites V. Détermination ab initio de potentiels électroniques pour le calcul de données spectroscopiques : Ab Initio Determination of Electronic Potentials for Spectroscopic Datas Computation. [Doctoral Dissertation]. Université Paris-Est; 2010. Available from: http://www.theses.fr/2010PEST1052

26. Brymora, Katarzyna. Modélisation des propriétés magnétiques et optiques de nanoparticules d’intérêt médical : Modeling of magnetic and optical properties of nanoparticles in medical interest.

Degree: Docteur es, Physique, 2013, Le Mans

URL: http://www.theses.fr/2013LEMA1015

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Cette thèse porte sur la modélisation ab initio des ligands et des nanoparticules magnétiques utilisés en médecine (hyperthermie magnétique, imagerie médicale ...). Les calculs sont… (more)

Subjects/Keywords: Nanoparticules magnétiques; DFT; Ab initio; Fonctionnalisation; Magnetic nanoparticles; DFT; Ab initio; Fonctionalization; 620.5

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Brymora, K. (2013). Modélisation des propriétés magnétiques et optiques de nanoparticules d’intérêt médical : Modeling of magnetic and optical properties of nanoparticles in medical interest. (Doctoral Dissertation). Le Mans. Retrieved from http://www.theses.fr/2013LEMA1015

Chicago Manual of Style (16^th Edition):

Brymora, Katarzyna. “Modélisation des propriétés magnétiques et optiques de nanoparticules d’intérêt médical : Modeling of magnetic and optical properties of nanoparticles in medical interest.” 2013. Doctoral Dissertation, Le Mans. Accessed April 21, 2021. http://www.theses.fr/2013LEMA1015.

MLA Handbook (7^th Edition):

Brymora, Katarzyna. “Modélisation des propriétés magnétiques et optiques de nanoparticules d’intérêt médical : Modeling of magnetic and optical properties of nanoparticles in medical interest.” 2013. Web. 21 Apr 2021.

Vancouver:

Brymora K. Modélisation des propriétés magnétiques et optiques de nanoparticules d’intérêt médical : Modeling of magnetic and optical properties of nanoparticles in medical interest. [Internet] [Doctoral dissertation]. Le Mans; 2013. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2013LEMA1015.

Council of Science Editors:

Brymora K. Modélisation des propriétés magnétiques et optiques de nanoparticules d’intérêt médical : Modeling of magnetic and optical properties of nanoparticles in medical interest. [Doctoral Dissertation]. Le Mans; 2013. Available from: http://www.theses.fr/2013LEMA1015

27. Cahier, Benjamin. Étude théorique de l'anisotropie magnétique dans des complexes de métaux de transition : application à des complexes mono- et binucléaires de Ni(II) et Co(II) : Theoretical approach to magnetic anisotropy in transition metal complexes : application to Ni(II) and Co(II) mono- and binuclear complexes.

Degree: Docteur es, Chimie, 2018, Université Paris-Saclay (ComUE)

URL: http://www.theses.fr/2018SACLS070

► Les molécules-aimants sont des complexes moléculaires contenant des ions des métaux de transition ou des lanthanides capables de présenter le phénomène de blocage de l’aimantation… (more)

▼ Les molécules-aimants sont des complexes moléculaires contenant des ions des métaux de transition ou des lanthanides capables de présenter le phénomène de blocage de l’aimantation en dessous d’une température de blocage Tb. Ce blocage est dû à la présence d’une barrière d’énergie de réorientation de leur aimantation à cause de la présence d’une anisotropie magnétique uniaxiale qui conduit à la présence de deux états stables de l’aimantation.Ces deux états stables sont adressables avec un champ magnétique extérieur. Il est donc,théoriquement, envisageable d’utiliser ces molécules comme unités de base pour le stockage « classique » de l’information.Néanmoins, à cause de la nature quantique des molécules, une relaxation entre les deux états de l’aimantation a lieu à basse température par effet tunnel à travers la barrière d’énergie. Cet effet tunnel a plusieurs causes dont une correspondant à une légère déviation de l’anisotropie magnétique de la situation strictement axiale. Cet effet annule le caractère bistable (classique) des molécules les rendant inutilisables comme bits classiques pour le stockage de l’information. Mais, la présence de l’effet tunnel conduit à une situation particulière à basse température où deux niveaux sont présents séparés par une énergie liée au caractère non axiale (rhombique) de l’aimantation (cas où le spin est entier). Un système à deux niveaux est appelé bit quantique(qubit) et constitue l’unité de base pour la construction d’ordinateurs quantiques si plusieurs conditions sont réunies.Ainsi, pour concevoir des bits classiques ou quantiques, il est indispensable comprendre au niveau microscopique la nature de l’anisotropie magnétique et les facteurs qui l’influencent.Ce travail de thèse est consacré à l’étude théorique de la nature de l’anisotropie magnétique dans des complexes mononucléaires et binucléaires de Ni(II) (S = 1)et de Co(II) (S = 3/2). Des calculs de type ab initio, basés sur la théorie de la fonction d’onde,qui permettent d’extraire les paramètres de l’hamiltonien de spin de l’anisotropie magnétique ont été effectués. Des calculs sur des objets modèles et molécules réelles qui permettent de séparer l’effet des différents paramètres structuraux et électroniques des ligands sur la nature et l’amplitude de l’anisotropie magnétique ont aussi été réalisés.La comparaison entre les calculs sur des complexes modèles et sur des complexes réels permet de rationaliser les propriétés magnétiques des complexes réels et surtout de proposer des stratégies pour la synthèse de nouveaux complexes avec les propriétés souhaitées. L’étude de complexes binucléaires qui peuvent être considérés comme la première étape pour la conception de porte logique quantique a été réalisée. Les calculs sur les complexes binucléaires sont réalisés en fragmentant les molécules en deux espèces mononucléaires. Pour les complexes binucléaires de Ni(II) et Co(II), des calculs de type Density Functional Theory (DFT) pour évaluer l’amplitude et la nature de l’interaction d’échange ont été menés. Pour étudier… Advisors/Committee Members: Mallah, Talal (thesis director), Guihery, Nathalie (thesis director).

Subjects/Keywords: Magnétisme moléculaire; Calculs ab initio; Molécules aimants; Molecular magnetism; Ab initio calculations; Single molecule magnets

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Cahier, B. (2018). Étude théorique de l'anisotropie magnétique dans des complexes de métaux de transition : application à des complexes mono- et binucléaires de Ni(II) et Co(II) : Theoretical approach to magnetic anisotropy in transition metal complexes : application to Ni(II) and Co(II) mono- and binuclear complexes. (Doctoral Dissertation). Université Paris-Saclay (ComUE). Retrieved from http://www.theses.fr/2018SACLS070

Chicago Manual of Style (16^th Edition):

Cahier, Benjamin. “Étude théorique de l'anisotropie magnétique dans des complexes de métaux de transition : application à des complexes mono- et binucléaires de Ni(II) et Co(II) : Theoretical approach to magnetic anisotropy in transition metal complexes : application to Ni(II) and Co(II) mono- and binuclear complexes.” 2018. Doctoral Dissertation, Université Paris-Saclay (ComUE). Accessed April 21, 2021. http://www.theses.fr/2018SACLS070.

MLA Handbook (7^th Edition):

Cahier, Benjamin. “Étude théorique de l'anisotropie magnétique dans des complexes de métaux de transition : application à des complexes mono- et binucléaires de Ni(II) et Co(II) : Theoretical approach to magnetic anisotropy in transition metal complexes : application to Ni(II) and Co(II) mono- and binuclear complexes.” 2018. Web. 21 Apr 2021.

Vancouver:

Cahier B. Étude théorique de l'anisotropie magnétique dans des complexes de métaux de transition : application à des complexes mono- et binucléaires de Ni(II) et Co(II) : Theoretical approach to magnetic anisotropy in transition metal complexes : application to Ni(II) and Co(II) mono- and binuclear complexes. [Internet] [Doctoral dissertation]. Université Paris-Saclay (ComUE); 2018. [cited 2021 Apr 21]. Available from: http://www.theses.fr/2018SACLS070.

Council of Science Editors:

Cahier B. Étude théorique de l'anisotropie magnétique dans des complexes de métaux de transition : application à des complexes mono- et binucléaires de Ni(II) et Co(II) : Theoretical approach to magnetic anisotropy in transition metal complexes : application to Ni(II) and Co(II) mono- and binuclear complexes. [Doctoral Dissertation]. Université Paris-Saclay (ComUE); 2018. Available from: http://www.theses.fr/2018SACLS070

Uniwersytet im. Adama Mickiewicza w Poznaniu

28. Mikulski, Damian. Teoretyczne badanie biofizykochemicznych właściwości resweratrolu i jego pochodnych .

Degree: 2011, Uniwersytet im. Adama Mickiewicza w Poznaniu

URL: http://hdl.handle.net/10593/947

► Trans-resweratrol to związek będący hydroksylową pochodną trans-stilbenu. Dowiedziono, że jest on silnym antyoksydantem, substancją antynowotworową, przeciwzapalną, antywirusową oraz antylipemiczną. Spośród wielu substancji aktywnych zawartych w… (more)

Subjects/Keywords: trans-resweratrol; trans-resveratrol; antyoksydanty; antioxidants; optymalizacja; optimisation; metody ab initio; ab initio method

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Mikulski, D. (2011). Teoretyczne badanie biofizykochemicznych właściwości resweratrolu i jego pochodnych . (Doctoral Dissertation). Uniwersytet im. Adama Mickiewicza w Poznaniu. Retrieved from http://hdl.handle.net/10593/947

Chicago Manual of Style (16^th Edition):

Mikulski, Damian. “Teoretyczne badanie biofizykochemicznych właściwości resweratrolu i jego pochodnych .” 2011. Doctoral Dissertation, Uniwersytet im. Adama Mickiewicza w Poznaniu. Accessed April 21, 2021. http://hdl.handle.net/10593/947.

MLA Handbook (7^th Edition):

Mikulski, Damian. “Teoretyczne badanie biofizykochemicznych właściwości resweratrolu i jego pochodnych .” 2011. Web. 21 Apr 2021.

Vancouver:

Mikulski D. Teoretyczne badanie biofizykochemicznych właściwości resweratrolu i jego pochodnych . [Internet] [Doctoral dissertation]. Uniwersytet im. Adama Mickiewicza w Poznaniu; 2011. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/10593/947.

Council of Science Editors:

Mikulski D. Teoretyczne badanie biofizykochemicznych właściwości resweratrolu i jego pochodnych . [Doctoral Dissertation]. Uniwersytet im. Adama Mickiewicza w Poznaniu; 2011. Available from: http://hdl.handle.net/10593/947

29. Koliogiorgos, Athanasios. Υπολογιστικές προσομοιώσεις από πρώτες αρχές της ηλεκτρονικής δομής συνήθων και υβριδικών αλογονούχων περοβσκιτικών υλικών.

Degree: 2019, University of Patras; Πανεπιστήμιο Πατρών

URL: http://hdl.handle.net/10442/hedi/45308

► Halide perovskites constitute a group of materials that have come under the spotlight in the search for novel photovoltaics and optoelectronic materials, thanks to their… (more)

▼ Halide perovskites constitute a group of materials that have come under the spotlight in the search for novel photovoltaics and optoelectronic materials, thanks to their multifold physical, chemical, optical end electronic properties. Characteristics like high carrier mobility and low synthesis cost have made them highly desirable especially in the field of solar cell technology. At the same time, their stability and toxicity issues put a barrier to their ability to be further incorporated into devices, and these issues need addressing. Computational study of their electronic structure constitutes an inseparable and essential part of their fabrication process, since electronic structure is the one characteristic from which all electronic properties that are much wanted by the experimental research flow. In this Doctoral dissertation, we have used first-principles, or ab-initio, computational tools that make use of Density Functional Theory (DFT) in order to study extensively and in depth a wide array of existing and novel perovskites, with the main objective of finding non-toxic materials with suitable energy bandgap. In parallel with the search for perovskites for photovoltaic applications, a recently and rapidly developing body of experimental research on perovskite nanostructures, such as quantum dots, is being observed. The reason for this is the combination of properties such as photoluminescence and high optical absorption and emission that these nanostructures manifest. However, there are hardly any extensive theoretical and computational studies to back up this experimental field. In view of this, we have also studied with first-principle and quantum chemistry simulations the electronic structure and optical absorption spectra of a similarly wide array of perovskite quantum dots, in order to lay the ground for further development in that field. A brief overview of the chapters of this dissertation will be now outlaid.Chapter One is a synopsis of the theory that lies behind first-principles calculations. The main points that are covered are: Schrödinger’s one-body equation and many-body approximations; DFT method and its aspects; functionals; wavefunction sets; pseudopotentials; Kohn-Sham equations and the self-consistent method of calculation. A qualitative discussion of electronic structure and energy gaps concludes this chapter.Chapter Two presents a general introduction to perovskite materials and the perovskite structure, with emphasis on the unit lattice structure and different crystal symmetries. We also take a first glance at halide perovskites, and present an overview of a halide perovskite solar cell device.Chapter Three follows a description of the two software simulation packages that were employed during this Doctoral course. These are the VASP and ORCA suites. The first program was used for ab-initio calculations on bulk materials with periodic crystal structure. The second package was employed for the special case of finite, low-dimensional structures that quantum dots are. We discuss…

Subjects/Keywords: Ab initio υπολογισμοί; Υπολογισμοί DFT; Περοβσκίτες; Ηλεκτρονική δομή; DFT; Ab initio calculations; Perovskites; Electronic structure

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Koliogiorgos, A. (2019). Υπολογιστικές προσομοιώσεις από πρώτες αρχές της ηλεκτρονικής δομής συνήθων και υβριδικών αλογονούχων περοβσκιτικών υλικών. (Thesis). University of Patras; Πανεπιστήμιο Πατρών. Retrieved from http://hdl.handle.net/10442/hedi/45308

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Chicago Manual of Style (16^th Edition):

Koliogiorgos, Athanasios. “Υπολογιστικές προσομοιώσεις από πρώτες αρχές της ηλεκτρονικής δομής συνήθων και υβριδικών αλογονούχων περοβσκιτικών υλικών.” 2019. Thesis, University of Patras; Πανεπιστήμιο Πατρών. Accessed April 21, 2021. http://hdl.handle.net/10442/hedi/45308.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

MLA Handbook (7^th Edition):

Koliogiorgos, Athanasios. “Υπολογιστικές προσομοιώσεις από πρώτες αρχές της ηλεκτρονικής δομής συνήθων και υβριδικών αλογονούχων περοβσκιτικών υλικών.” 2019. Web. 21 Apr 2021.

Vancouver:

Koliogiorgos A. Υπολογιστικές προσομοιώσεις από πρώτες αρχές της ηλεκτρονικής δομής συνήθων και υβριδικών αλογονούχων περοβσκιτικών υλικών. [Internet] [Thesis]. University of Patras; Πανεπιστήμιο Πατρών; 2019. [cited 2021 Apr 21]. Available from: http://hdl.handle.net/10442/hedi/45308.

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Council of Science Editors:

Koliogiorgos A. Υπολογιστικές προσομοιώσεις από πρώτες αρχές της ηλεκτρονικής δομής συνήθων και υβριδικών αλογονούχων περοβσκιτικών υλικών. [Thesis]. University of Patras; Πανεπιστήμιο Πατρών; 2019. Available from: http://hdl.handle.net/10442/hedi/45308

Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

30. Rommel Bezerra Viana. Estudo químico-quântico de compostos de fósforo: estabilidade e propriedades eletrônicas.

Degree: 2013, University of São Paulo

URL: http://www.teses.usp.br/teses/disponiveis/75/75134/tde-23042013-104953/

►

Os compostos de fósforo apresentam várias implicações em processos atmosféricos e interestelares. Nesta tese, será realizado um estudo ab initio em três diferentes sistemas. (i)… (more)

▼

Os compostos de fósforo apresentam várias implicações em processos atmosféricos e interestelares. Nesta tese, será realizado um estudo ab initio em três diferentes sistemas. (i) Um destes sistemas é o radical PCO. No capítulo três, foi analisado os aspectos conformacionais do radical PCO, sendo avaliado as propriedades moleculares e termodinâmicas da espécie cíclica e das espécies lineares. Entre os isômeros do radical PCO, a espécie i3 (C∞V, 2π) é a mais estável delas, com uma entalpia de formação a 0K de 22.33±2.10 kcal mol-1. Considerando as barreiras de energia, que convergem em direção a espécie i3, elas apresentam valores próximos de 10 kcal mol-1, ao passo que a energia necessária para a isomerização da molécula i3 para outros isômeros é acima de 60 kcal mol-1. Estes valores de energia explicam o fato que, em condições experimentais, foi detectado apenas a espécie i3 (C∞V, 2π). (ii) No capítulo quatro, foi elucidado o mecanismo da reação PH3 +F, assim como foi também caracterizado as propriedades eletrônicas dos intermediários observados nesta reação. Na reação PH3 +F, pode ser observado que, diferente da literatura, dois caminhos são possíveis para esta reação: (a) a reação de abstração de hidrogênio, com a formação dos produtos PH2 e HF, e a reação de adição-eliminação, com a formação das espécies PH2F e H. Analisando a energia eletrônica, é possível observar que a reação de adição-eliminação apresenta uma barreira de energia de 23 kcal mol-1 abaixo da mesma observada para a reação de abstração de hidrogênio. Considerando os intermediários formados na reação PH3 + F, são observados dois tipos de simetria: uma C1 e duas Cs. Além disso, a entalpia de formação em 298K dos intermediários variou de -22.99 to -29.74 kcal mol-1. (iii) No capítulo cinco, foi avaliada a interação da fosfina com diferentes aglomerados de água. Neste capítulo, foi realizada uma análise nos aglomerados PH3-(H2O)n (n=1-8,12,20) e avaliado a estabilidade dos potenciais isômeros, assim como as propriedades moleculares e espectroscópicas dos diferentes isômeros. Nas estruturas PH3-(H2O)n (n=1-8) foi possível observar que os modos vibracionais δ(PH3) e δsym(PH3) apresentaram um deslocamento para o vermelho, ao passo que as freqüências de estiramento simétrico e assimétrico da fosfina apresentaram um deslocamento para o azul. No caso da estrutura PH3(H2O)20, as variações nos modos vibracionais foram similares embora que mais intensas, sendo o mesmo também observado para as respectivas intensidades. Além disso, a energia necessária para o confinamento da fosfina no interior de um aglomerado de água dodecaedro hexagonal variou de -1.81 to -6.38 kcal mol-1.

The phosphorus compounds show several implications to atmospheric and interstellar processes. In this thesis, was performed an ab initio study on three different systems. (i) One of these systems is the PCO radical. In chapter three, was studied the conformation aspects of PCO radicals, which was assessed the molecular and thermodynamic…

Advisors/Committee Members: Albérico Borges Ferreira da Silva, Rodrigo Queiroz de Albuquerque, Victor Marcelo Deflon, Luiz Guilherme Machado de Macêdo, Aguinaldo Robinson de Souza.

Subjects/Keywords: ab initio; astroquímica; CCSD(T); interestelar; ab initio; astrochemistry; CCSD(T); interstellar

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6^th Edition):

Viana, R. B. (2013). Estudo químico-quântico de compostos de fósforo: estabilidade e propriedades eletrônicas. (Doctoral Dissertation). University of São Paulo. Retrieved from http://www.teses.usp.br/teses/disponiveis/75/75134/tde-23042013-104953/

Chicago Manual of Style (16^th Edition):

Viana, Rommel Bezerra. “Estudo químico-quântico de compostos de fósforo: estabilidade e propriedades eletrônicas.” 2013. Doctoral Dissertation, University of São Paulo. Accessed April 21, 2021. http://www.teses.usp.br/teses/disponiveis/75/75134/tde-23042013-104953/.

MLA Handbook (7^th Edition):

Viana, Rommel Bezerra. “Estudo químico-quântico de compostos de fósforo: estabilidade e propriedades eletrônicas.” 2013. Web. 21 Apr 2021.

Vancouver:

Viana RB. Estudo químico-quântico de compostos de fósforo: estabilidade e propriedades eletrônicas. [Internet] [Doctoral dissertation]. University of São Paulo; 2013. [cited 2021 Apr 21]. Available from: http://www.teses.usp.br/teses/disponiveis/75/75134/tde-23042013-104953/.

Council of Science Editors:

Viana RB. Estudo químico-quântico de compostos de fósforo: estabilidade e propriedades eletrônicas. [Doctoral Dissertation]. University of São Paulo; 2013. Available from: http://www.teses.usp.br/teses/disponiveis/75/75134/tde-23042013-104953/

Open Access Theses and Dissertations