You searched for subject:(Density functional theory)
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1.
wang, lei.
Flow Equation Approach to the Hybrid DFT – Anderson Model
Description of Actinide Compounds.
Degree: PhD, Physics, 2016, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:674096/
► Safe storage and disposal of spent fuel rods from nuclear power plants calls for the ability to model actinide complexes and compounds in the environment.…
(more)
▼ Safe storage and disposal of spent fuel rods from
nuclear power plants calls for the ability to model actinide
complexes and compounds in the environment. The rich behavior of
actinide ions may be traced to the valence electrons, especially
those in the 5f shell. The electronic configuration of neutral
uranium, for instance, is [Rn]5f
36d17s2. Typically the valence
6d and 7s electrons transfer to other atoms leaving active 5f
orbitals that are relatively localized. Quantitative calculations
of actinide reactions must overcome several obstacles. The crucial
physics of relativity must be included. The Amsterdam
Density
Functional (ADF) and NWChem
density functional theory (DFT)
packages incorporate relativistic effects, and are used to model
various uranium compounds species (UO
2F
42- /
UO
2F
4-, UO
2Cl
42- / UO
2Cl
4-, UF
5- /
UF
5, UCl
5- / UCl
5, UF
6- / UF
6, and UCl
6- /
UCl
6). The converged geometry and bond lengths are consistent,
and also close those predicted by coupled-cluster calculations and
experimental measurements. But incorporating the physics of strong
electronic correlations among the 5f electrons presents a greater
challenge as these are poorly captured by DFT. The adiabatic
detachment energy (ADE) obtained from DFT alone can differ by as
much as 1.0 eV from experimental measurement. In order to solve
this problem, a hybrid approach is adopted that uses DFT to
construct a generalized many-body Anderson impurity model of the
frontier orbitals. The continuous unitary transformation (flow
equation) approach and a truncation scheme are introduced to bridge
the independent-particle model and many-body Anderson impurity
model. This is necessary because the Hilbert space dimension of the
impurity model is exponentially large. The flow equation and
truncation scheme can efficiently decouple orbital states of the
uranium compounds species that hybridize less with 5f uranium
orbitals to decrease the dimension. Exact diagonalization of the
resulting sparse matrix corrects the adiabatic detachment energy
obtained from DFT alone. The hybrid DFT / many-body approach yields
ADE values that differ by order of 0.1 eV from
experiment.
Advisors/Committee Members: Marston, John (Director), Wang, Lai-Sheng (Reader), Stratt, Richard (Reader).
Subjects/Keywords: Density Functional Theory
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APA (6th Edition):
wang, l. (2016). Flow Equation Approach to the Hybrid DFT – Anderson Model
Description of Actinide Compounds. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:674096/
Chicago Manual of Style (16th Edition):
wang, lei. “Flow Equation Approach to the Hybrid DFT – Anderson Model
Description of Actinide Compounds.” 2016. Doctoral Dissertation, Brown University. Accessed February 27, 2021.
https://repository.library.brown.edu/studio/item/bdr:674096/.
MLA Handbook (7th Edition):
wang, lei. “Flow Equation Approach to the Hybrid DFT – Anderson Model
Description of Actinide Compounds.” 2016. Web. 27 Feb 2021.
Vancouver:
wang l. Flow Equation Approach to the Hybrid DFT – Anderson Model
Description of Actinide Compounds. [Internet] [Doctoral dissertation]. Brown University; 2016. [cited 2021 Feb 27].
Available from: https://repository.library.brown.edu/studio/item/bdr:674096/.
Council of Science Editors:
wang l. Flow Equation Approach to the Hybrid DFT – Anderson Model
Description of Actinide Compounds. [Doctoral Dissertation]. Brown University; 2016. Available from: https://repository.library.brown.edu/studio/item/bdr:674096/

Wake Forest University
2.
Arter, Calvin.
FIRST-PRINCIPLES MODELING OF MOF74 FOR GAS SEQUESTRATION AND STORAGE APPLICATIONS.
Degree: 2016, Wake Forest University
URL: http://hdl.handle.net/10339/59283
► The problems associated with anthropogenic climate change arise from the reliance on fossil fuels for energy and the greenhouse gas emissions that are produced. A…
(more)
▼ The problems associated with anthropogenic climate change arise from the reliance on fossil fuels for energy and the greenhouse gas emissions that are produced. A two-fold solution to reversing the effects from anthropogenic climate change involves finding a clean alternative fuel source and mitigating the amount of greenhouse gases that will be continued to be produced and those that are already in the atmosphere. I present work in this thesis that is able to address both problems. Metal organic framework (MOF) materials are highly-tunable porous materials with affinities toward small-molecule uptake. In particular, I look to study and improve a particular MOF, i.e. MOF74, as a viable hydrogen storage material and carbon capture tool. This is done through first-principles calculations with a focus on correctly describing van der Waals interactions in order to best model small-molecule adsorption inside the pore of MOF74.
Subjects/Keywords: Density Functional Theory
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APA ·
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APA (6th Edition):
Arter, C. (2016). FIRST-PRINCIPLES MODELING OF MOF74 FOR GAS SEQUESTRATION AND STORAGE APPLICATIONS. (Thesis). Wake Forest University. Retrieved from http://hdl.handle.net/10339/59283
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Arter, Calvin. “FIRST-PRINCIPLES MODELING OF MOF74 FOR GAS SEQUESTRATION AND STORAGE APPLICATIONS.” 2016. Thesis, Wake Forest University. Accessed February 27, 2021.
http://hdl.handle.net/10339/59283.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Arter, Calvin. “FIRST-PRINCIPLES MODELING OF MOF74 FOR GAS SEQUESTRATION AND STORAGE APPLICATIONS.” 2016. Web. 27 Feb 2021.
Vancouver:
Arter C. FIRST-PRINCIPLES MODELING OF MOF74 FOR GAS SEQUESTRATION AND STORAGE APPLICATIONS. [Internet] [Thesis]. Wake Forest University; 2016. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/10339/59283.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Arter C. FIRST-PRINCIPLES MODELING OF MOF74 FOR GAS SEQUESTRATION AND STORAGE APPLICATIONS. [Thesis]. Wake Forest University; 2016. Available from: http://hdl.handle.net/10339/59283
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Tulane University
3.
Dougherty, Kelly J.
Synthesis of compounds with very large specific rotations.
Degree: 2020, Tulane University
URL: https://digitallibrary.tulane.edu/islandora/object/tulane:120370
► [email protected]
A search in a research database for “large specific rotation” or anything similar produces few articles. Large specific rotation is not commonly used…
(more)
▼ [email protected]
A search in a research database for “large specific rotation” or anything similar produces few articles. Large specific rotation is not commonly used as an indicator for extraordinary chiroptical response. Alternatively, anisotropy factors obtained from circular dichroism spectra and calculated rotational strengths are more widely used to gauge chiroptical response. To another point, a search for “large chiroptical response” gives few articles that discuss pure organic compounds, and the result list is populated by organometallic clusters, nanostructures, and thin films. A search of the Reaxys database for organic compounds with [α]Ds larger than 1000 revealed that there are about 600, and there are only two that have [α]Ds larger than 10,000.30 We wondered if we could design a compound that would break the record in specific rotation and possess extraordinary chiroptical properties.
Guided by time-dependent density functional theory (TD-DFT) calculations, various chiral, polycyclic aromatic compounds (PACs) were chosen as candidates to display extraordinary chiroptical properties, such as high optical rotation, strong circular dichroism, or a high degree of circularly polarized luminescence (CPL). PACs comprise a large class of organic compounds. In addition to synthetic PACs, numerous naturally occurring PACs exist in coal tar and as decomposition products of organic material. Since their pi electrons are delocalized, PACs have interesting and possibly useful electronic properties and a variety of applications. The PACs described in this dissertation, e.g., helical mesobenzanthrones, a cyclophane, are twisted pentacenes are chiral and have interesting optoelectronic properties. TD-DFT was primarily used to predict which compounds had the greatest potential to yield record-breaking specific rotations or other chiroptical properties, and ordinary DFT calculation were used to determine if these compounds had sufficiently high racemization barriers to be resolved at room temperature. With regard to specific rotation, the accuracy of TD-DFT calculations was examined by comparing experimental specific rotations to the calculated values.
1
Kelly Jane Dougherty
Advisors/Committee Members: Pascal, Jr., Robert A. (Thesis advisor), School of Science & Engineering Chemistry (Degree granting institution).
Subjects/Keywords: time-dependent density functional theory
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Dougherty, K. J. (2020). Synthesis of compounds with very large specific rotations. (Thesis). Tulane University. Retrieved from https://digitallibrary.tulane.edu/islandora/object/tulane:120370
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Dougherty, Kelly J. “Synthesis of compounds with very large specific rotations.” 2020. Thesis, Tulane University. Accessed February 27, 2021.
https://digitallibrary.tulane.edu/islandora/object/tulane:120370.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Dougherty, Kelly J. “Synthesis of compounds with very large specific rotations.” 2020. Web. 27 Feb 2021.
Vancouver:
Dougherty KJ. Synthesis of compounds with very large specific rotations. [Internet] [Thesis]. Tulane University; 2020. [cited 2021 Feb 27].
Available from: https://digitallibrary.tulane.edu/islandora/object/tulane:120370.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Dougherty KJ. Synthesis of compounds with very large specific rotations. [Thesis]. Tulane University; 2020. Available from: https://digitallibrary.tulane.edu/islandora/object/tulane:120370
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of New South Wales
4.
Pham, Anh.
Theoretical investigation of novel spin-polarized materials for spintronic applications.
Degree: Materials Science & Engineering, 2014, University of New South Wales
URL: http://handle.unsw.edu.au/1959.4/54145
;
https://unsworks.unsw.edu.au/fapi/datastream/unsworks:13290/SOURCE02?view=true
► Development of spin-polarized materials is important for the realization of spintronic devices. Two approaches are taken: (i) investigating magnetism in diluted magnetic semiconductors (DMSs), and…
(more)
▼ Development of spin-polarized materials is important for the realization of spintronic devices. Two approaches are taken: (i) investigating magnetism in diluted magnetic semiconductors (DMSs), and (ii) developing novel 2D materials with intrinsic spin currents. The focus of this thesis is to study these two classes of materials using the
density functional (DFT)
theory.The first part focuses on ZnO based DMS. The systematic study of C/N doped ZnO with defects shows that ZnO:C exhibits ferromagnetism, but dopant complex C2 tends to inhibit this property. Most importantly, the computational method plays a key role in studying DMS. Due to the popularity of hydrogenated ZnO:Co, this system is tested using the different methods. The DFT+U method shows a very specific configuration of hydrogenated Co complex can generate ferromagnetism. The inadequacies of traditional method are further exposed when the dopant geometry is compared between the hybrid
functional method and normal DFT. The hybrid method includes the Fock exchange which significantly improves the description of long-range inter-atomic forces in the geometry relaxation yielding a more accurate description. The second part focuses on the study of novel 2D materials with. The studies are devoted to increase the band gap of of novel 2D materials. In silicene and germanene, it is shown that the adsorption and substitution of Tl can increase the bandgaps to 0.29 eV at a small doping limit of ~2%. In addition, Tl can also tune the conductivity of silicene from n to p types depending on the doping sites, and preserving the high mobility of the undoped structure. Furthermore, the author also predicts several new wide bandgap quantum spin Hall insulator (QSHI). QSHI is a novel material with an insulating bulk state and spin-polarized metallic edges. By modifying the surfaces through hydrogenation, the orbital interactions of Bi, Pb, Cr, Mo, and W in the low energy level are confined on two dimensional resulting in novel QSHI with giant gap and strongly correlated property. These results represent important contribution to the study of spintronic materials. First, the understanding between the theoretical method and magnetic properties in semiconductors can help to accurately predict new spintronic materials. Most importantly, the study in orbital engineering of 2D materials with hydrogenation provides new insights into the nature topological materials which have practical applications for the next generation of electronic devices.
Advisors/Committee Members: Li, Sean, Materials Science & Engineering, Faculty of Science, UNSW.
Subjects/Keywords: Magnetism; Density functional theory; Spintronics
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pham, A. (2014). Theoretical investigation of novel spin-polarized materials for spintronic applications. (Doctoral Dissertation). University of New South Wales. Retrieved from http://handle.unsw.edu.au/1959.4/54145 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:13290/SOURCE02?view=true
Chicago Manual of Style (16th Edition):
Pham, Anh. “Theoretical investigation of novel spin-polarized materials for spintronic applications.” 2014. Doctoral Dissertation, University of New South Wales. Accessed February 27, 2021.
http://handle.unsw.edu.au/1959.4/54145 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:13290/SOURCE02?view=true.
MLA Handbook (7th Edition):
Pham, Anh. “Theoretical investigation of novel spin-polarized materials for spintronic applications.” 2014. Web. 27 Feb 2021.
Vancouver:
Pham A. Theoretical investigation of novel spin-polarized materials for spintronic applications. [Internet] [Doctoral dissertation]. University of New South Wales; 2014. [cited 2021 Feb 27].
Available from: http://handle.unsw.edu.au/1959.4/54145 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:13290/SOURCE02?view=true.
Council of Science Editors:
Pham A. Theoretical investigation of novel spin-polarized materials for spintronic applications. [Doctoral Dissertation]. University of New South Wales; 2014. Available from: http://handle.unsw.edu.au/1959.4/54145 ; https://unsworks.unsw.edu.au/fapi/datastream/unsworks:13290/SOURCE02?view=true

Oregon State University
5.
Schulte, Jeff B.
Hard spheres within classical density functional theory and Min proteins in Escherichia coli.
Degree: PhD, Physics, 2015, Oregon State University
URL: http://hdl.handle.net/1957/55645
► This thesis reports on computational research in two different areas. I first discuss the Min-protein system found within Escherichia coli. Following this I discuss an…
(more)
▼ This thesis reports on computational research in two different areas. I first discuss the Min-protein system found within Escherichia coli. Following this I discuss an extended investigation into improving free energy functionals that are used within Classical
Density Functional Theory in order to model water. Chapter 2 examines the dynamics of the Min-protein system within E. Coli, which aid in regulating the process of cell division by identifying the center of the cell. While this system usually exhibits robust bipolar oscillations in a variety of cell shapes, recent experiments have shown that when the cells are mechanically deformed into wide, flattened out, irregular shapes, the spatial regularity of these oscillations breaks down. We employ widely used stochastic and deterministic models of the Min system to simulate cells with flattened shapes. The deterministic model predicts regular bipolar oscillations, in contradiction with the experimentally observed behavior, while the single molecule nature of the stochastic model, which is based on the same reaction-diffusion equations, leads to the disruption of the regular patterns of protein concentration. We further report on simulations of symmetric but flattened cell shapes, and find that it is the flattening and accompanying lateral expansion rather than the asymmetry of the cell shapes that causes the irregular oscillation behavior. Chapter 3 begins our discussion of Classical
Density Functional Theory research by introducing many of the key concepts used in the following chapters. Chapter 4 investigates the value of the distribution function of an inhomogeneous hard-sphere fluid at contact. This quantity plays a critical role in statistical associating fluid
theory, which is the basis of a number of recently developed classical
density functionals, including ones developed within my research group. We define two averaged values for the distribution function at contact and derive formulas for each of them from the White Bear version of the fundamental measure
theory functional, using an assumption of thermodynamic consistency. We test these formulas, as well as two existing formulas, against Monte Carlo simulations and find excellent agreement between the Monte Carlo data and one of our averaged distribution functions. Chapter 5 details our modifications of our recently published statistical associating fluid
theory-based classical
density functional theory for water, incorporating this improved distribution function at contact. We examine the effect of this alteration by studying two hard-sphere solutes and a Lennard-Jones approximation of a krypton-atom solute, and find improvement. Finally, Chapter 6 introduces an approximation for the pair distribution function of the inhomogeneous hard sphere fluid. Our approximation makes use of the new distribution function at contact referred to above. This approach achieves greater computational efficiency than previous approaches by enabling the use of exclusively fixed-kernel convolutions, which allows for an…
Advisors/Committee Members: Roundy, David J. (advisor), Jansen, Henri J. (committee member).
Subjects/Keywords: Classical Density Functional Theory; Density functionals
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Schulte, J. B. (2015). Hard spheres within classical density functional theory and Min proteins in Escherichia coli. (Doctoral Dissertation). Oregon State University. Retrieved from http://hdl.handle.net/1957/55645
Chicago Manual of Style (16th Edition):
Schulte, Jeff B. “Hard spheres within classical density functional theory and Min proteins in Escherichia coli.” 2015. Doctoral Dissertation, Oregon State University. Accessed February 27, 2021.
http://hdl.handle.net/1957/55645.
MLA Handbook (7th Edition):
Schulte, Jeff B. “Hard spheres within classical density functional theory and Min proteins in Escherichia coli.” 2015. Web. 27 Feb 2021.
Vancouver:
Schulte JB. Hard spheres within classical density functional theory and Min proteins in Escherichia coli. [Internet] [Doctoral dissertation]. Oregon State University; 2015. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1957/55645.
Council of Science Editors:
Schulte JB. Hard spheres within classical density functional theory and Min proteins in Escherichia coli. [Doctoral Dissertation]. Oregon State University; 2015. Available from: http://hdl.handle.net/1957/55645

NSYSU
6.
Chang, Ching-Sheng.
A combination of Molecular dynamics, FIRE algorithm, and Density functional theory on structural and catalytic characteristics of Titania nanoparticle.
Degree: Master, Mechanical and Electro-Mechanical Engineering, 2008, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0824108-215353
► In order to understand the structural and electronic properties of titanium oxide nanoparticles of different sizes, the FIRE algorithm combining the simulated annealing method is…
(more)
▼ In order to understand the structural and electronic properties of titanium oxide nanoparticles of different sizes, the FIRE algorithm combining the simulated annealing method is employed to find the structures of TinO2n (n=1ï¼6) nanoparticles with the global minimum potential energy. To deeply understand electronic properties, the relaxation structures of TinO2n (n=1ï¼6) nanoparticle from previous method will be recalculated by
density functional theory (DFT) method. The Fukui function, Frontier Molecular Orbital and
density of state of TinO2n (n=1ï¼6) nanoparticles are discussed for understanding the size effect of TiO2 nanoparticles on chemical reactivity.
The adsorption and dissociation energy mechanism of the HN3 molecule and its fragments are also discussed and are compared with the mechanism about HN3 on the anatase surface.
Advisors/Committee Members: Ju, Shin-Pon (committee member), Sun, Shi-Jie (chair), Chang, Jee-Gong (chair), Chen, Hui-Lung (chair), Chen, Hsin-Tsung (chair).
Subjects/Keywords: Molecular Dynamics; Density functional theory; FIRE algorithm
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Chang, C. (2008). A combination of Molecular dynamics, FIRE algorithm, and Density functional theory on structural and catalytic characteristics of Titania nanoparticle. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0824108-215353
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Chang, Ching-Sheng. “A combination of Molecular dynamics, FIRE algorithm, and Density functional theory on structural and catalytic characteristics of Titania nanoparticle.” 2008. Thesis, NSYSU. Accessed February 27, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0824108-215353.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Chang, Ching-Sheng. “A combination of Molecular dynamics, FIRE algorithm, and Density functional theory on structural and catalytic characteristics of Titania nanoparticle.” 2008. Web. 27 Feb 2021.
Vancouver:
Chang C. A combination of Molecular dynamics, FIRE algorithm, and Density functional theory on structural and catalytic characteristics of Titania nanoparticle. [Internet] [Thesis]. NSYSU; 2008. [cited 2021 Feb 27].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0824108-215353.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Chang C. A combination of Molecular dynamics, FIRE algorithm, and Density functional theory on structural and catalytic characteristics of Titania nanoparticle. [Thesis]. NSYSU; 2008. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0824108-215353
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

NSYSU
7.
Lin, Wen-huan.
Decoupling of graphene from SiC(0001) surface by Au intercalation : A first-principles study.
Degree: Master, Physics, 2011, NSYSU
URL: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0214111-140556
► The atomic and electronic structures of Au-intercalated graphene buffer layer on SiC(0001) surface were investigated using first-principles calculations. The unique Dirac cone of the graphene…
(more)
▼ The atomic and electronic structures of Au-intercalated graphene buffer layer on SiC(0001) surface were investigated using first-principles calculations. The unique Dirac cone of the graphene near K point reappeared as the buffer layer was intercalated by Au atoms. Coherence interfaces were used to study the mismatch and strain at the interfaces. Our calculations showed that the strain at graphene/Au and Au/SiC(0001) interfaces also played a key role in the electronic structures. Futhermore, we found that at Au coverage of 3/8 ML, Au intercalation leads to strong n-type doping of graphene. At 9/8 ML, it exhibited weak p-type doping, meaning that graphene is not fully decoupled from substrate. The shift of Dirac point resulting from electronic doping is not only due to different electronegativities but also strains at the interfaces. Our calculated positions of Dirac points are consistent with those observed in the ARPES experiment [Isabella Gierz et al., Phys. Rev. B 81, 235408 (2010).].
Advisors/Committee Members: Wan-Sheng Su (chair), Wang-Chi Yeh (chair), Feng-Chuan Chuang (committee member), Chien-Cheng Kuo (chair).
Subjects/Keywords: graphene; SiC; Dirac point; density functional theory
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Lin, W. (2011). Decoupling of graphene from SiC(0001) surface by Au intercalation : A first-principles study. (Thesis). NSYSU. Retrieved from http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0214111-140556
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lin, Wen-huan. “Decoupling of graphene from SiC(0001) surface by Au intercalation : A first-principles study.” 2011. Thesis, NSYSU. Accessed February 27, 2021.
http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0214111-140556.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lin, Wen-huan. “Decoupling of graphene from SiC(0001) surface by Au intercalation : A first-principles study.” 2011. Web. 27 Feb 2021.
Vancouver:
Lin W. Decoupling of graphene from SiC(0001) surface by Au intercalation : A first-principles study. [Internet] [Thesis]. NSYSU; 2011. [cited 2021 Feb 27].
Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0214111-140556.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lin W. Decoupling of graphene from SiC(0001) surface by Au intercalation : A first-principles study. [Thesis]. NSYSU; 2011. Available from: http://etd.lib.nsysu.edu.tw/ETD-db/ETD-search/view_etd?URN=etd-0214111-140556
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
8.
Lehtinen, Petri Olavi.
Magnetic Nature of Intrinsic Carbon Defects.
Degree: 2005, Helsinki University of Technology
URL: http://lib.tkk.fi/Diss/2005/isbn951227521X/
► Magnetism is a phenomenon that has been known for a very long time. Iron, cobalt, and nickel are known ferromagnetic materials. It is less known,…
(more)
▼ Magnetism is a phenomenon that has been known for a very long time. Iron, cobalt, and nickel are known ferromagnetic materials. It is less known, probably because it is so unexpected, that even carbon can have ferromagnetic behaviour. Experimentally this has been confirmed on many occasions within the last decade. Ferromagnetic behaviour of carbon provides an example of the fact that magnetism is not well understood at the atomic scale. One of the aims of this thesis is to study and understand possible sources of ferromagnetism in carbon systems, thereby creating a possible foundation for the next generation of ferromagnets. Carbon itself is a very interesting substance with numerous interesting properties. In the late 1980s and early 1990s new carbon allotropes were found, such as fullerenes (bucky balls) and nanotubes (cylinders), next to the old ones (graphite and diamond). Especially nanotubes have been considered as candidates for several future applications. Whatever the fabrication process, all allotropes of carbon will have intrinsic defects, and in this thesis the role of these defects in carbon magnetism is investigated in detail. Studying magnetism requires "state-of-the-art"-methods due to the demand of high accuracy because energy differences between non-magnetic and magnetic cases are usually very small. Ab initio methods are usually the best for such studies, especially methods based on the density functional theory. Here, a state-of-art method which is based on the density functional theory and implementing projector augmented waves to model the properties of carbon is used. Adatoms and vacancies are found to have magnetic moments of 0.5 μB and 1.0 μB, respectively. In practice, however, the high mobility of adatoms on graphene at room temperature would suggest that many of them recombine with vacancies or cluster together, destroying their magnetism. Despite the indications that a barrier to vacancy-interstitial pair recombination exists, efficient recombination seems to be confirmed by He-irradiation experiments. The magnetic signal was small despite the fact that the amount of defects created by the He ions is large. Also, the effect of the changing electronic structure on the magnetic moments of adatoms and vacancies is studied with the help of nanotubes. On nanotubes, the magnetism of an adatom decreases because of the curvature and differences in electronic structures while the magnetic moment of a vacancy in all but strongly metallic tubes is destroyed. The experimental demonstration of induced ferromagnetism by proton irradiation on graphite indicates a promising direction for creating a magnetic carbon system in a controllable way. Simulations indicate that this is due to a combination of a hydrogen atom trapping at vacancies and pinning of mobile adatoms, producing magnetic C-H complexes and uncompensated vacancies.
Dissertations / Laboratory of Physics, Helsinki University of Technology, ISSN 1455-1802; 129
Advisors/Committee Members: Helsinki University of Technology, Department of Engineering Physics and Mathematics, Laboratory of Physics.
Subjects/Keywords: density functional theory; carbon; graphite; nanotube; magnetism
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APA (6th Edition):
Lehtinen, P. O. (2005). Magnetic Nature of Intrinsic Carbon Defects. (Thesis). Helsinki University of Technology. Retrieved from http://lib.tkk.fi/Diss/2005/isbn951227521X/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Lehtinen, Petri Olavi. “Magnetic Nature of Intrinsic Carbon Defects.” 2005. Thesis, Helsinki University of Technology. Accessed February 27, 2021.
http://lib.tkk.fi/Diss/2005/isbn951227521X/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Lehtinen, Petri Olavi. “Magnetic Nature of Intrinsic Carbon Defects.” 2005. Web. 27 Feb 2021.
Vancouver:
Lehtinen PO. Magnetic Nature of Intrinsic Carbon Defects. [Internet] [Thesis]. Helsinki University of Technology; 2005. [cited 2021 Feb 27].
Available from: http://lib.tkk.fi/Diss/2005/isbn951227521X/.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Lehtinen PO. Magnetic Nature of Intrinsic Carbon Defects. [Thesis]. Helsinki University of Technology; 2005. Available from: http://lib.tkk.fi/Diss/2005/isbn951227521X/
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
9.
Witte, Jonathon Kendall.
Development and Assessment of Electronic Structure Approaches for Non-Covalent Interactions.
Degree: Chemistry, 2017, University of California – Berkeley
URL: http://www.escholarship.org/uc/item/7mc3k8tm
► This thesis is primarily concerned with the development and assessment of electronic structure approaches for intermolecular interactions. Various aspects of existing approaches – most notably…
(more)
▼ This thesis is primarily concerned with the development and assessment of electronic structure approaches for intermolecular interactions. Various aspects of existing approaches – most notably the choices of method, grid, and basis set – are examined with respect to performance in novel ways, and new semi-empirical corrections intended to rectify deficiencies in standard methods are introduced.
Subjects/Keywords: Chemistry; Physics; density functional theory; electronic structure
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APA (6th Edition):
Witte, J. K. (2017). Development and Assessment of Electronic Structure Approaches for Non-Covalent Interactions. (Thesis). University of California – Berkeley. Retrieved from http://www.escholarship.org/uc/item/7mc3k8tm
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Witte, Jonathon Kendall. “Development and Assessment of Electronic Structure Approaches for Non-Covalent Interactions.” 2017. Thesis, University of California – Berkeley. Accessed February 27, 2021.
http://www.escholarship.org/uc/item/7mc3k8tm.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Witte, Jonathon Kendall. “Development and Assessment of Electronic Structure Approaches for Non-Covalent Interactions.” 2017. Web. 27 Feb 2021.
Vancouver:
Witte JK. Development and Assessment of Electronic Structure Approaches for Non-Covalent Interactions. [Internet] [Thesis]. University of California – Berkeley; 2017. [cited 2021 Feb 27].
Available from: http://www.escholarship.org/uc/item/7mc3k8tm.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Witte JK. Development and Assessment of Electronic Structure Approaches for Non-Covalent Interactions. [Thesis]. University of California – Berkeley; 2017. Available from: http://www.escholarship.org/uc/item/7mc3k8tm
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Cornell University
10.
Zhuang, Houlong.
Computational Discovery And Design Of Novel Single-Layer Materials For Electronic And Energy Applications.
Degree: PhD, Materials Science and Engineering, 2014, Cornell University
URL: http://hdl.handle.net/1813/36085
► The last decade has seen an explosion of interest in two-dimensional materials, which now can be synthesized in either single or a few atomic layer…
(more)
▼ The last decade has seen an explosion of interest in two-dimensional materials, which now can be synthesized in either single or a few atomic layer forms. The discovery of novel fabrication methods for creating single-layer materials such as graphene, zinc oxide, silicon carbide, boron nitride, and molybdenum disulfide has opened a new field of materials research with promising applications for energy technologies. Single-layer materials not only represent the ultimate scaling in the vertical direction, but also show a variety of novel and useful electronic, optical, and mechanical properties. Using a data-mining and first-principles design approach we identify several previously unrecognized families of single-layer materials. We determine their energetic and dynamical stability, study their electronic and optical properties, and determine their suitability for electronic and energy applications using a combination of
density-
functional calculations with semi-local and hybrid
density functionals, the many-body G0 W0 method, and the Bethe-Salpeter equation. To determine their suitability for photocatalytic water splitting we also determine their solubility in water. We discover several single-layer materials with promising properties for electronic devices such as for dielectric barriers in graphene field-effect tunneling transistors and for photocatalytic water splitting. Our results provide guidance for experimental synthesis efforts and future searches of materials suitable for applications in electronic device and energy technologies.
Advisors/Committee Members: Hennig, Richard G. (chair), Schlom, Darrell (committee member), Muller, David Anthony (committee member).
Subjects/Keywords: Single-layer materials; Density-functional theory; Semiconductors
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MLA ·
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CSE |
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APA (6th Edition):
Zhuang, H. (2014). Computational Discovery And Design Of Novel Single-Layer Materials For Electronic And Energy Applications. (Doctoral Dissertation). Cornell University. Retrieved from http://hdl.handle.net/1813/36085
Chicago Manual of Style (16th Edition):
Zhuang, Houlong. “Computational Discovery And Design Of Novel Single-Layer Materials For Electronic And Energy Applications.” 2014. Doctoral Dissertation, Cornell University. Accessed February 27, 2021.
http://hdl.handle.net/1813/36085.
MLA Handbook (7th Edition):
Zhuang, Houlong. “Computational Discovery And Design Of Novel Single-Layer Materials For Electronic And Energy Applications.” 2014. Web. 27 Feb 2021.
Vancouver:
Zhuang H. Computational Discovery And Design Of Novel Single-Layer Materials For Electronic And Energy Applications. [Internet] [Doctoral dissertation]. Cornell University; 2014. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1813/36085.
Council of Science Editors:
Zhuang H. Computational Discovery And Design Of Novel Single-Layer Materials For Electronic And Energy Applications. [Doctoral Dissertation]. Cornell University; 2014. Available from: http://hdl.handle.net/1813/36085

Vanderbilt University
11.
Cook, Brandon Girard.
Quantum transport in nanodevices.
Degree: PhD, Physics, 2012, Vanderbilt University
URL: http://hdl.handle.net/1803/13739
► First-principles simulations of quantum transport in nano-devices are presented in this dissertation. First, the extension of the complex absorbing potential quantum transport framework to the…
(more)
▼ First-principles simulations of quantum transport in nano-devices are presented in this dissertation. First, the extension of the complex absorbing potential quantum transport framework to the general case of N electrodes is developed. This framework is used with
density functional theory to investigate, grids of nanowires, graphene cross junctions and a six terminal carbon nanotube device. Quantum interference between possible paths for electrons was found to have a pronounced effect in multi-terminal systems. The charge transport properties of kinked nanowires, kinked graphene nanoribbons, elongated gold nanowires and a molecular junction with gold electrodes are analyzed with
density functional and transport calculations. The simulations show the importance of atomic features and highlight the care needed to create
functional devices, particularly in the case of kinked structures. Finally, interfaces between graphene and carbon nanotubes and graphene and MoS2 are studied. In the case of graphene-carbon nanotube junctions the p-type Schottky barrier was found to be low compared to the barrier in standard Palladium-nanotube junctions. Graphene was found to be a favorable electrode material for the injection of electrons into MoS2 due to the low potential barrier and presence of delocalized states near the Fermi energy. In addition to the analysis of these physical systems, a number of advanced computational algorithms were developed.
Advisors/Committee Members: Yaqiong Xu (committee member), Kirill Bolotin (committee member), David Ernst (committee member), Sokrates Pantelides (committee member), Kalman Varga (Committee Chair).
Subjects/Keywords: density functional theory; quantum electron transport
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APA ·
Chicago ·
MLA ·
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CSE |
Export
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APA (6th Edition):
Cook, B. G. (2012). Quantum transport in nanodevices. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/13739
Chicago Manual of Style (16th Edition):
Cook, Brandon Girard. “Quantum transport in nanodevices.” 2012. Doctoral Dissertation, Vanderbilt University. Accessed February 27, 2021.
http://hdl.handle.net/1803/13739.
MLA Handbook (7th Edition):
Cook, Brandon Girard. “Quantum transport in nanodevices.” 2012. Web. 27 Feb 2021.
Vancouver:
Cook BG. Quantum transport in nanodevices. [Internet] [Doctoral dissertation]. Vanderbilt University; 2012. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1803/13739.
Council of Science Editors:
Cook BG. Quantum transport in nanodevices. [Doctoral Dissertation]. Vanderbilt University; 2012. Available from: http://hdl.handle.net/1803/13739

Vanderbilt University
12.
Driscoll, Joseph Andrew.
Electron field emission in nanostructures: A first-principles study.
Degree: PhD, Physics, 2011, Vanderbilt University
URL: http://hdl.handle.net/1803/10782
► This dissertation presents the study of electron field emission from nanostructures using a first-principles computational framework. Field emission is studied under various conditions such as…
(more)
▼ This dissertation presents the study of electron field emission from nanostructures using a first-principles computational framework. Field emission is studied under various conditions such as laser illumination, spin polarization, and the presence of adsorbates. Several nanostructures are considered (carbon nanowires, graphene nanoribbons, and nanotubes of varying composition) which allow general conclusions to be made.
The calculations are performed using a real-space, real-time implementation of time-dependent
density functional theory. In addition to field emission results, we also present rigorous evaluations of basis sets and complex absorbing potentials, both of which are needed in order to allow these demanding calculations to be performed efficiently.
The best basis choice (e.g., atomic orbitals or real-space grids) depends on the structure of the system being analyzed and the physical processes involved (e.g., laser illumination). For this reason, it was important to conduct thorough tests of basis set performance, in terms of accuracy and computational efficiency.
In non-periodic systems, emitted electron
density can experience non-physical reflections from boundaries of the calculation volume, leading to inaccuracies. To prevent this, we used complex absorbing potentials (CAPs) to absorb
density before
it could reach the boundaries. We evaluate CAPs using test cases relevant to field emission calculations.
Our results show that the adsorbate atoms studied significantly increase the field emission current of carbon nanotubes. We also show that short laser pulses can cause nanostructures to emit electrons with very high spatial and time resolutions. The
results predict that GaN, SiC, and Si nanotubes are particularly good field emitters. The highest-current nanotube, Si, is predicted to produce currents an order of magnitude higher than BN or C nanotubes. Carbon nanotubes with various adsorbates are
shown to be able to emit spin-polarized current. These are the first first-principles calculations showing spin-polarized field emission for carbon nanotubes with iron adsorbates. Finally, our results suggest that graphene nanoribbons could be extremely good field emitters. The results and computational methods discussed provide a
foundation for future theoretical work in nanoscale field emission.
Advisors/Committee Members: Sait Umar (committee member), Ronald Schrimpf (committee member), Sokrates Pantelides (committee member), Charles Brau (committee member), Kalman Varga (Committee Chair).
Subjects/Keywords: density functional theory; nanotubes; nanostructures; field emission
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Driscoll, J. A. (2011). Electron field emission in nanostructures: A first-principles study. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10782
Chicago Manual of Style (16th Edition):
Driscoll, Joseph Andrew. “Electron field emission in nanostructures: A first-principles study.” 2011. Doctoral Dissertation, Vanderbilt University. Accessed February 27, 2021.
http://hdl.handle.net/1803/10782.
MLA Handbook (7th Edition):
Driscoll, Joseph Andrew. “Electron field emission in nanostructures: A first-principles study.” 2011. Web. 27 Feb 2021.
Vancouver:
Driscoll JA. Electron field emission in nanostructures: A first-principles study. [Internet] [Doctoral dissertation]. Vanderbilt University; 2011. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1803/10782.
Council of Science Editors:
Driscoll JA. Electron field emission in nanostructures: A first-principles study. [Doctoral Dissertation]. Vanderbilt University; 2011. Available from: http://hdl.handle.net/1803/10782

Vanderbilt University
13.
Pennycook, Timothy John.
Density functional theory and scanning transmission electron microscopy: synergistic tools for materials investigation.
Degree: PhD, Physics, 2012, Vanderbilt University
URL: http://hdl.handle.net/1803/10460
► A combination of first principles density functional calculations and aberration corrected scanning transmission electron microscopy is used to investigate a number of topical issues in…
(more)
▼ A combination of first principles
density functional calculations and aberration corrected scanning transmission electron microscopy is used to investigate a number of topical issues in condensed matter and materials physics: Structural and optical properties of magnesium doped alumina; the origin of colossal ionic conductivity in oxide multilayers; Atom-by-atom identification of point defects in single layer boron nitride with annular dark field STEM and DFT; Hybrid
density functional theory applied to LCMO; Optical gaps of free and embedded Si nanoclusters; Origin of white light emission from CdSe nanoclusters. In each of these cases the underlying physics of the respective phenomena was elucidated.
Advisors/Committee Members: Prof. Sandra J. Rosenthal (committee member), Prof. Kalman Varga (committee member), Dr. Mark P. Oxley (committee member), Prof. Sokrates T. Pantelides (Committee Chair), Dr. Maria Varela (Committee Chair).
Subjects/Keywords: scanning transmission electron microscopy; density functional theory
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Pennycook, T. J. (2012). Density functional theory and scanning transmission electron microscopy: synergistic tools for materials investigation. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/10460
Chicago Manual of Style (16th Edition):
Pennycook, Timothy John. “Density functional theory and scanning transmission electron microscopy: synergistic tools for materials investigation.” 2012. Doctoral Dissertation, Vanderbilt University. Accessed February 27, 2021.
http://hdl.handle.net/1803/10460.
MLA Handbook (7th Edition):
Pennycook, Timothy John. “Density functional theory and scanning transmission electron microscopy: synergistic tools for materials investigation.” 2012. Web. 27 Feb 2021.
Vancouver:
Pennycook TJ. Density functional theory and scanning transmission electron microscopy: synergistic tools for materials investigation. [Internet] [Doctoral dissertation]. Vanderbilt University; 2012. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1803/10460.
Council of Science Editors:
Pennycook TJ. Density functional theory and scanning transmission electron microscopy: synergistic tools for materials investigation. [Doctoral Dissertation]. Vanderbilt University; 2012. Available from: http://hdl.handle.net/1803/10460

Vanderbilt University
14.
Brock, Casey Neil.
Automated Optimization of Pseudopotentials for Faster and More Accurate Plane Wave Density Functional Theory Calculations in Materials.
Degree: PhD, Interdisciplinary Materials Science, 2019, Vanderbilt University
URL: http://hdl.handle.net/1803/12328
► In principle, the properties of materials are determined by the behavior of electrons. Therefore quantum mechanical electronic structure calculations play a critical role in materials…
(more)
▼ In principle, the properties of materials are determined by the behavior of electrons. Therefore quantum mechanical electronic structure calculations play a critical role in materials modeling. These calculations owe much of their success in materials research to speed improvements enabled by the pseudopotential approximation to
density functional theory (DFT). However, new pseudopotentials still need to be developed to meet the accuracy and speed demands of the materials design framework. The goal of this research is thus to improve on previous generations of pseudopotentials using automated searches for optimal pseudopotential parameters. In this dissertation, I show that optimizations using a multi-objective genetic algorithm can improve the accuracy and speed of pseudopotentials compared to those previously published in the literature. Additionally, I propose a new scattering property metric for pseudopotentials based on the arctangent of the logderivatives, which can cheaply identify ghost states and logderivative disagreements. This metric is key for enabling automated pseudopotential optimization, and facilitates reporting of the accuracy of published pseudopotentials. Finally, I demonstrate the automated design of a gallium pseudopotential using the arctangent metric, which results in a 40% speedup of defect calculations in gallium nitride.
Advisors/Committee Members: Kirk H. Bevan (committee member), Cary L. Pint (committee member), Peter T. Cummings (committee member), D. Greg Walker (Committee Chair), Kalman Varga (Committee Chair).
Subjects/Keywords: pseudopotentials; density functional theory; electronic structure
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Brock, C. N. (2019). Automated Optimization of Pseudopotentials for Faster and More Accurate Plane Wave Density Functional Theory Calculations in Materials. (Doctoral Dissertation). Vanderbilt University. Retrieved from http://hdl.handle.net/1803/12328
Chicago Manual of Style (16th Edition):
Brock, Casey Neil. “Automated Optimization of Pseudopotentials for Faster and More Accurate Plane Wave Density Functional Theory Calculations in Materials.” 2019. Doctoral Dissertation, Vanderbilt University. Accessed February 27, 2021.
http://hdl.handle.net/1803/12328.
MLA Handbook (7th Edition):
Brock, Casey Neil. “Automated Optimization of Pseudopotentials for Faster and More Accurate Plane Wave Density Functional Theory Calculations in Materials.” 2019. Web. 27 Feb 2021.
Vancouver:
Brock CN. Automated Optimization of Pseudopotentials for Faster and More Accurate Plane Wave Density Functional Theory Calculations in Materials. [Internet] [Doctoral dissertation]. Vanderbilt University; 2019. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1803/12328.
Council of Science Editors:
Brock CN. Automated Optimization of Pseudopotentials for Faster and More Accurate Plane Wave Density Functional Theory Calculations in Materials. [Doctoral Dissertation]. Vanderbilt University; 2019. Available from: http://hdl.handle.net/1803/12328

Penn State University
15.
Wang, Yuanxi.
Theory of two-dimensional materials: synthesis, properties, and structural engineering.
Degree: 2016, Penn State University
URL: https://submit-etda.libraries.psu.edu/catalog/3b591857h
► In this dissertation, I study the synthesis (and post-synthesis modifications), properties, and structural engineering of two-dimensional materials, using atomistic modeling techniques such as empirical forcefields…
(more)
▼ In this dissertation, I study the synthesis (and post-synthesis modifications), properties, and structural engineering of two-dimensional materials, using atomistic modeling techniques such as empirical forcefields and
density functional theory. The dissertation is divided into four parts. The first part consists of four chapters: in Chapters 1-3 I give an overview on
density functional theory and how vibrational properties and optical properties can be calculated within the DFT framework; in Chapter 4 a brief review on two-dimensional materials is given.
The second part is devoted to the synthesis and post-synthesis modifications of two-dimensional materials. In Chapter 5 I investigate the intercalation of hexagonal boron nitride and graphite using Bronsted acids such as H3PO4. DFT calculations show that dipolar interactions between acids molecules and the 2D sheets drive the intercalation process.
In Chapter 6 I study stripe patterns of W and Mo atoms in triangular monolayers of WxMo1-xS2 alloys. DFT calculations suggest that stripe ordering is kinetically driven, governed by fluctuations in local thermodynamic conditions during growth. In addition, I show that the striped phase alloy is electronically isotropic but vibrationally anisotropic, due to the nearly-identical electronic properties but very different atomic masses of Mo and W.
The third part is devoted to computation of vibrational and optical properties of molybdenum and tungsten disulfides. In Chapter 7 we investigate the optical signatures of defect-bound excitons in monolayer WS2. I show that the optical transitions between the highest valence band and mid-gap states introduced by sulfur vacancy defects have finite transition matrix elements. These results agrees with the measured photoluminescence spectra of monolayer WS2 grown by chemical vapor deposition, where spatially resolved photoluminescence at low temperatures revealed two bound excitons. To explain the anomaly in the thermal activation energy of the bound exciton, we propose that excitons are bound to negatively charged defects where two channels of radiative recombinations are allowed.
Chapter 8 focuses on intervalley scattering processes in monolayer MoS2, as probed by resonance raman spectroscopy, where the incident laser energy is varied across the A and B excitonic levels. We focus on two Raman peaks that are dispersive, a clear signature of second-order processes involving intervalley scattering. Using group
theory and DFT calculations, selection rules are established for intervalley scattering processes
mediated by acoustic phonons.
In Chapter 9 I investigate Second Harmonic Generation (SHG) in monolayer WS2. Its second order nonlinear susceptibility is nearly three orders of magnitude larger than other common nonlinear crystals.
Density functional theory calculations suggest that the origin of the large nonlinear susceptibility lies in resonance enhancement and sharp features in the joint
density of states.
In the final part, I explore possible methods of manipulating the…
Advisors/Committee Members: Vincent Henry Crespi, Dissertation Advisor/Co-Advisor, Vincent Henry Crespi, Committee Chair/Co-Chair, Jorge Osvaldo Sofo, Committee Member, Mauricio Terrones Maldonado, Committee Member, Thomas E Mallouk, Outside Member.
Subjects/Keywords: two-dimensional materials; density functional theory
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Wang, Y. (2016). Theory of two-dimensional materials: synthesis, properties, and structural engineering. (Thesis). Penn State University. Retrieved from https://submit-etda.libraries.psu.edu/catalog/3b591857h
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Wang, Yuanxi. “Theory of two-dimensional materials: synthesis, properties, and structural engineering.” 2016. Thesis, Penn State University. Accessed February 27, 2021.
https://submit-etda.libraries.psu.edu/catalog/3b591857h.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Wang, Yuanxi. “Theory of two-dimensional materials: synthesis, properties, and structural engineering.” 2016. Web. 27 Feb 2021.
Vancouver:
Wang Y. Theory of two-dimensional materials: synthesis, properties, and structural engineering. [Internet] [Thesis]. Penn State University; 2016. [cited 2021 Feb 27].
Available from: https://submit-etda.libraries.psu.edu/catalog/3b591857h.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Wang Y. Theory of two-dimensional materials: synthesis, properties, and structural engineering. [Thesis]. Penn State University; 2016. Available from: https://submit-etda.libraries.psu.edu/catalog/3b591857h
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Kwame Nkrumah University of Science and Technology
16.
Opoku, Ernest; Arhin, Grace; Pipim, George Baffour; Adams, Anita Houston; Tia, Richard.
Site‑, enantio‑ and stereo‑selectivities of the 1,3‑dipolar cycloaddition reactions of oxanorbornadiene with C,N‑disubstituted nitrones and dimethyl nitrilimines: a DFT mechanistic study.
Degree: 2020, Kwame Nkrumah University of Science and Technology
URL: Theoretical
Chemistry
Accounts
(2020)
139:16
https://doi.org/10.1007/s00214-019-2529-8
;
http://dspace.knust.edu.gh:8080/jspui/handle/123456789/12659
► 1,3-Dipolar cycloaddition of nitrones to oxanorbornadienes is an important method for the enantioselective synthesis of highly substituted 5-membered heterocycles such as furans and isoxazolidines, which…
(more)
▼ 1,3-Dipolar cycloaddition of nitrones to oxanorbornadienes is an important method for the enantioselective synthesis of highly substituted 5-membered heterocycles such as furans and isoxazolidines, which have high utility in the chemical and pharmaceutical industries. The mechanism of the reaction and the effects of substituents on the (3 + 2) cycloaddition reactions (32CA) of C,N-dialkyl nitrones with a series of substituted oxanorbornadienes have been studied with focus on the site-selectivity (attack on the more substituted double bond of the oxanorbornadiene derivatives versus attack on the less substituted double bond), enantioselectivity and stereo-selectivity using density functional theory calculations at the M06/6-311++G(d,p) of theory. The results showed that the addition step to form the bicyclic isoxazolidines cycloadducts has generally low barriers compared to the cycloreversion step which converts the cycloadducts into furans and monocyclic isoxazolidines. Generally, electron-withdrawing substituents favour the nitrone attack on the highly substituted double bond, while electron-donating substituents favour the attack on less substituted double bond. The R enantiomers are generally favoured over the S enantiomers, and exo stereo-isomers are generally favoured over the endo stereo-isomers, irrespective of substituents.
An article published by Springer-Verlag GmbH Germany and also available at https://doi.org/10.1007/s00214-019-2529-8
KNUST
Subjects/Keywords: Dipole; Oxanorbornadiene; Nitrone; Enantioselectivity; Density functional theory
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MLA ·
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APA (6th Edition):
Opoku, Ernest; Arhin, Grace; Pipim, George Baffour; Adams, Anita Houston; Tia, R. (2020). Site‑, enantio‑ and stereo‑selectivities of the 1,3‑dipolar cycloaddition reactions of oxanorbornadiene with C,N‑disubstituted nitrones and dimethyl nitrilimines: a DFT mechanistic study. (Thesis). Kwame Nkrumah University of Science and Technology. Retrieved from Theoretical Chemistry Accounts (2020) 139:16 https://doi.org/10.1007/s00214-019-2529-8 ; http://dspace.knust.edu.gh:8080/jspui/handle/123456789/12659
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Opoku, Ernest; Arhin, Grace; Pipim, George Baffour; Adams, Anita Houston; Tia, Richard. “Site‑, enantio‑ and stereo‑selectivities of the 1,3‑dipolar cycloaddition reactions of oxanorbornadiene with C,N‑disubstituted nitrones and dimethyl nitrilimines: a DFT mechanistic study.” 2020. Thesis, Kwame Nkrumah University of Science and Technology. Accessed February 27, 2021.
Theoretical Chemistry Accounts (2020) 139:16 https://doi.org/10.1007/s00214-019-2529-8 ; http://dspace.knust.edu.gh:8080/jspui/handle/123456789/12659.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Opoku, Ernest; Arhin, Grace; Pipim, George Baffour; Adams, Anita Houston; Tia, Richard. “Site‑, enantio‑ and stereo‑selectivities of the 1,3‑dipolar cycloaddition reactions of oxanorbornadiene with C,N‑disubstituted nitrones and dimethyl nitrilimines: a DFT mechanistic study.” 2020. Web. 27 Feb 2021.
Vancouver:
Opoku, Ernest; Arhin, Grace; Pipim, George Baffour; Adams, Anita Houston; Tia R. Site‑, enantio‑ and stereo‑selectivities of the 1,3‑dipolar cycloaddition reactions of oxanorbornadiene with C,N‑disubstituted nitrones and dimethyl nitrilimines: a DFT mechanistic study. [Internet] [Thesis]. Kwame Nkrumah University of Science and Technology; 2020. [cited 2021 Feb 27].
Available from: Theoretical Chemistry Accounts (2020) 139:16 https://doi.org/10.1007/s00214-019-2529-8 ; http://dspace.knust.edu.gh:8080/jspui/handle/123456789/12659.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Opoku, Ernest; Arhin, Grace; Pipim, George Baffour; Adams, Anita Houston; Tia R. Site‑, enantio‑ and stereo‑selectivities of the 1,3‑dipolar cycloaddition reactions of oxanorbornadiene with C,N‑disubstituted nitrones and dimethyl nitrilimines: a DFT mechanistic study. [Thesis]. Kwame Nkrumah University of Science and Technology; 2020. Available from: Theoretical Chemistry Accounts (2020) 139:16 https://doi.org/10.1007/s00214-019-2529-8 ; http://dspace.knust.edu.gh:8080/jspui/handle/123456789/12659
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

Université de Neuchâtel
17.
Battaglia, Corsin.
Structural and electronic properties of self-assembled
nanostructures on silicon surfaces.
Degree: 2008, Université de Neuchâtel
URL: http://doc.rero.ch/record/9568
► Cette thèse présente de nouveaux résultats sur les nanostructures auto-assemblées sur surfaces de silicium étudiées par différentes techniques complémentaires: la microscopie et spectroscopie tunnel (STM/STS)…
(more)
▼ Cette thèse présente de nouveaux résultats sur les
nanostructures auto-assemblées sur surfaces de silicium étudiées
par différentes techniques complémentaires: la microscopie et
spectroscopie tunnel (STM/STS) à basse température, la diffraction
dynamique d'électron de basse énergie (LEED), la spectroscopie de
photoélectrons résolue en angle (ARPES) ainsi que des calculs "ab
initio" réalisés dans le cadre de la théorie de la fonctionnelle de
densité (DFT). A mesure que la taille des dispositifs
électroniques, magnétiques et optiques s'approche du régime
nanométrique, la compréhension des phénomènes quantiques présents
sur les surfaces semiconductrices est de plus en plus importante
pour la science et pour la technologie. Nous investiguons ici les
propriétés structurales et électroniques à l'échelle atomique de la
reconstruction Si(331)-(12£1), ainsi que des chaînes atomiques
auto-assemblées sur la surface de Si(111). La surface de Si(331)
est importante puisque c'est la seule surface plane de silicium qui
présente une reconstruction stable avec une orientation comprise
entre les directions (111) et (110). Après avoir optimisé la
méthode de préparation de la surface, nous sommes désormais
capables d'obtenir des régions de taille quasi micrométrique où
l'arrangement atomique ne présente presque aucun défaut. Cette
perfection sans précédent de la surface, combinée avec son
anisotropie structurale prononcée, font de cette surface un
candidat prometteur pour guider la croissance auto-assemblée de
réseaux de nanostructures hétéro-épitaxiales. Depuis sa découverte
datant de plus de 17 ans, plusieurs modèles structuraux ont été
proposés. Cependant, aucun de ces modèles n'a été capable
d'expliquer nos images STM à haute résolution. En exploitant la
complémentarité de STM, LEED et DFT, nous proposons un nouveau
modèle structural pour la reconstruction i(331)-(12£1) et discutons
sa stabilité et ses propriétés électroniques. Nous nous focalisons
ensuite sur les mécanismes sous-jacents de l'auto-assemblage des
chaînes atomiques sur la surface de Si(111). Ces nanostructures ont
suscité un énorme intérêt en raison de leurs propriétés
électroniques quasi uni-dimensionnelles. En se basant sur la
combinaison de nos études STM et LEED, nous proposons un nouveau
modèle structural pour les chaînes atomiques induites par le Gd.
Nous concluons qu'outre les adsorbats mono- et divalents, les
adsorbats trivalents sont aussi capables de stabiliser des chaînes
atomiques. Ceci établit les chaînes constituées de silicium du type
"honeycomb" et "Seiwatz" comme blocs de construction universels
dans les reconstructions de chaîne atomiques induites par les
adsorbats. La systèmatique dans l'auto-assemblage est expliquée en
reliant l'état de valence de l'adsorbat aux symétries accessibles
des chaînes. Nous examinons encore théoriquement la stabilité des
différentes phases de chaînes en utilisant des méthodes de calculs
de structure électronique "ab initio" et comparons nos résultats
aux expériences.
Advisors/Committee Members: Philipp (Dir.).
Subjects/Keywords: density functional theory
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Battaglia, C. (2008). Structural and electronic properties of self-assembled
nanostructures on silicon surfaces. (Thesis). Université de Neuchâtel. Retrieved from http://doc.rero.ch/record/9568
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Battaglia, Corsin. “Structural and electronic properties of self-assembled
nanostructures on silicon surfaces.” 2008. Thesis, Université de Neuchâtel. Accessed February 27, 2021.
http://doc.rero.ch/record/9568.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Battaglia, Corsin. “Structural and electronic properties of self-assembled
nanostructures on silicon surfaces.” 2008. Web. 27 Feb 2021.
Vancouver:
Battaglia C. Structural and electronic properties of self-assembled
nanostructures on silicon surfaces. [Internet] [Thesis]. Université de Neuchâtel; 2008. [cited 2021 Feb 27].
Available from: http://doc.rero.ch/record/9568.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Battaglia C. Structural and electronic properties of self-assembled
nanostructures on silicon surfaces. [Thesis]. Université de Neuchâtel; 2008. Available from: http://doc.rero.ch/record/9568
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation

University of Manitoba
18.
Singh, Simarpreet.
Computational investigations of reactivity and selectivity in addition reactions.
Degree: Chemistry, 2018, University of Manitoba
URL: http://hdl.handle.net/1993/33677
► The development and application of density functional theory (DFT) on real chemical systems has allowed experimentalists to use computational chemistry, without an understanding of mathematical…
(more)
▼ The development and application of
density functional theory (DFT) on real chemical
systems has allowed experimentalists to use computational chemistry, without an understanding of mathematical details behind it, as a tool alongside experimental techniques in elucidation of reaction mechanisms.
In chapter 2, DFT methods are utilized to investigate the regio- and stereo-selectivity of
organocatalytic asymmetric ε-functionalization of furfural derivatives via trienamine activation. The role of the bifunctional aminocatalyst with hydrogen bonding abilities for the observed selectivity was investigated. The transition states were also calculated to understand the experimental results. Other heterocyclic such as thiophene, pyrrole and cyclopentadiene were also investigated to understand the role of heteroatom on reactivity of trienamine.
In chapter 3, DFT methods were used to understand the effect of chain length on reactivity of S-alkyl-thiatriazine scaffolds. The competition between inter- and intra-molecular substitutionreactions was explored. The conformations of S-alkyl-thiatriazine and barrier heights of both pathways played important roles for preference of one reaction over another.
Advisors/Committee Members: Davis, Rebecca (Chemistry) (supervisor), Schweizer, Frank (Chemistry).
Subjects/Keywords: Density Functional Theory; Organocatalysis; Asymmetric Synthesis
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Singh, S. (2018). Computational investigations of reactivity and selectivity in addition reactions. (Masters Thesis). University of Manitoba. Retrieved from http://hdl.handle.net/1993/33677
Chicago Manual of Style (16th Edition):
Singh, Simarpreet. “Computational investigations of reactivity and selectivity in addition reactions.” 2018. Masters Thesis, University of Manitoba. Accessed February 27, 2021.
http://hdl.handle.net/1993/33677.
MLA Handbook (7th Edition):
Singh, Simarpreet. “Computational investigations of reactivity and selectivity in addition reactions.” 2018. Web. 27 Feb 2021.
Vancouver:
Singh S. Computational investigations of reactivity and selectivity in addition reactions. [Internet] [Masters thesis]. University of Manitoba; 2018. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1993/33677.
Council of Science Editors:
Singh S. Computational investigations of reactivity and selectivity in addition reactions. [Masters Thesis]. University of Manitoba; 2018. Available from: http://hdl.handle.net/1993/33677

Rice University
19.
Zhang, Yuchong.
Thermodynamic Modeling of Branched Molecular Systems.
Degree: PhD, Engineering, 2019, Rice University
URL: http://hdl.handle.net/1911/106015
► Presence of branches in the molecular structure results in properties different from that of linear molecules and also leads to special industrial value and diverse…
(more)
▼ Presence of branches in the molecular structure results in properties different from that of linear molecules and also leads to special industrial value and diverse novel applications. However, a basic knowledge of thermodynamics of branched molecules is lacking. Experimental data for branched molecules are far less abundant compared with linear molecules and are usually questionable under harsh conditions such as high temperature and high pressure. Therefore, the goal of this thesis is to enhance our understanding of the phase behavior and microstructure of branched molecules using statistical mechanics based theories.
A new equation of state based on statistical associating fluid
theory (SAFT) is developed and applied to isomeric alkanes. The branching effect is explicitly accounted and the results are in good agreement with experimental data. The
density functional theory (DFT) version of SAFT, modified iSAFT, is applied to study conformations of branched polymers of special architecture, such as dendrimer and bottlebrush polymers. Related parameters such as molecule size, solvent quality and temperature that affect the phase behavior of these polymers have been investigated. The theoretical results are qualitatively consistent with experimental observations and are also validated by molecular simulation. In addition, several
functional polymers are studied, where we see potential lower critical solution temperature (LCST) behavior of an associating dendrimer and partially hidden conformations of an amphiphilic bottlebrush polymer.
The theories and models developed for branched molecules in this thesis are proved to not only be able to explain and support existent experimental results, but also have strong prediction ability where there is no data at all. These models will provide physical insight and helpful guidance for the design and application of branched molecules.
Advisors/Committee Members: Chapman, Walter G. (advisor).
Subjects/Keywords: Thermodynamics; Branched Molecules; SAFT; Density Functional Theory
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Zhang, Y. (2019). Thermodynamic Modeling of Branched Molecular Systems. (Doctoral Dissertation). Rice University. Retrieved from http://hdl.handle.net/1911/106015
Chicago Manual of Style (16th Edition):
Zhang, Yuchong. “Thermodynamic Modeling of Branched Molecular Systems.” 2019. Doctoral Dissertation, Rice University. Accessed February 27, 2021.
http://hdl.handle.net/1911/106015.
MLA Handbook (7th Edition):
Zhang, Yuchong. “Thermodynamic Modeling of Branched Molecular Systems.” 2019. Web. 27 Feb 2021.
Vancouver:
Zhang Y. Thermodynamic Modeling of Branched Molecular Systems. [Internet] [Doctoral dissertation]. Rice University; 2019. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/1911/106015.
Council of Science Editors:
Zhang Y. Thermodynamic Modeling of Branched Molecular Systems. [Doctoral Dissertation]. Rice University; 2019. Available from: http://hdl.handle.net/1911/106015

Victoria University of Wellington
20.
Leeb, Nina.
Tracking the Source of Enantioselectivity.
Degree: 2015, Victoria University of Wellington
URL: http://hdl.handle.net/10063/4906
► Enantioselectivity remains one of synthetic chemistry’s most formidable problems. It arises due to the formation of diastereomeric species in a reaction, either in the form…
(more)
▼ Enantioselectivity remains one of synthetic chemistry’s most formidable problems. It arises due to the formation of diastereomeric species in a reaction, either in the form of diastereomeric intermediates or a set of diastereomeric transition states. Without control a racemic mixture is formed. A resolution method is then required to separate the enantiomers. Any given resolution method will rely on the differing energies of diastereomers to allow for their separation. Experimentally there are a myriad of different options that may be used to induce separation; for example chromatography and/or crystallisation. The actual process that occurs through- out this separation has not, however, been fully investigated in all cases. A better understanding of the process is able to provide an understanding of how resolution methods work i.e. when diastereomers occur and how great their energy differences are. This is vital in increasing the efficiency and effectiveness of any given resolution method. This theoretical study completed an investigation of the reaction pathway between the enantiomers of 2-formyl-3-hydroxyl[2.2]paracyclophane (FHPC) with (S)-valyl-(S)-valine. A subsequent investigation of an alternative resolution method, involving (R)-α-PEAM, was also conducted. This latter resolution method was proposed experimentally as a simpler method that could aid in improving the separation of the enantiomers. This investigation was carried out using
Density Functional Theory (DFT) with the PBE0
functional and the triple-ζ TZVP basis set. The complete reaction profile was determined and diastereomeric intermediates and transition states for both resolution methods along two different pathways were determined; the ‘N-deprotonation Pathway’ and the ‘O-deprotonation Pathway’. The inadequacy of the first resolution method was found to be due to the presence of copper(II). Furthermore it was discovered that the re- action for both pathways would most likely proceed through the ‘O-deprotonation Pathway’ due to the barriers being lower in energy.
Advisors/Committee Members: Lein, Matthias.
Subjects/Keywords: DFT; Chiral resolution; Cyclophane; Density Functional Theory
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Leeb, N. (2015). Tracking the Source of Enantioselectivity. (Masters Thesis). Victoria University of Wellington. Retrieved from http://hdl.handle.net/10063/4906
Chicago Manual of Style (16th Edition):
Leeb, Nina. “Tracking the Source of Enantioselectivity.” 2015. Masters Thesis, Victoria University of Wellington. Accessed February 27, 2021.
http://hdl.handle.net/10063/4906.
MLA Handbook (7th Edition):
Leeb, Nina. “Tracking the Source of Enantioselectivity.” 2015. Web. 27 Feb 2021.
Vancouver:
Leeb N. Tracking the Source of Enantioselectivity. [Internet] [Masters thesis]. Victoria University of Wellington; 2015. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/10063/4906.
Council of Science Editors:
Leeb N. Tracking the Source of Enantioselectivity. [Masters Thesis]. Victoria University of Wellington; 2015. Available from: http://hdl.handle.net/10063/4906

Virginia Tech
21.
Li, Zheng.
Accelerating Catalyst Discovery via Ab Initio Machine Learning.
Degree: PhD, Chemical Engineering, 2019, Virginia Tech
URL: http://hdl.handle.net/10919/95915
► Machine learning and deep learning techniques have revolutionized a range of industries in recent years and have huge potential to improve every aspect of our…
(more)
▼ Machine learning and deep learning techniques have revolutionized a range of industries in recent years and have huge potential to improve every aspect of our daily lives. Essentially, machine-learning provides algorithms the ability to automatically discover the hidden patterns of data without being explicitly programmed. Because of this, machine learning models have gained huge successes in applications such as website recommendation systems, online fraud detection, robotic technologies, image recognition, etc. Nevertheless, implementing machine-learning techniques in the field of catalyst design remains difficult due to 2 primary challenges. The first challenge is our insufficient knowledge about the structure-property relationships for diverse material systems. Typically, developing a physically intuitive material feature method requests in-depth expert knowledge about the underlying physics of the material system and it is always an active field. The second challenge is the lack of training data in academic research. In many cases, collecting a sufficient amount of training data is not always feasible due to the limitation of computational/experimental resources. Subsequently, the machine learning model optimized with small data tends to be over-fitted and could provide biased predictions with huge uncertainties. To address the above-mentioned challenges, this thesis focus on the development of robust feature methods and strategies for a variety of catalyst systems using the
density functional theory (DFT) calculations. Through the case studies in the chapters, we show that the bulk electronic structure characteristics are successful features for capturing the adsorption properties of metal alloys and metal oxides. While molecular graphs are robust features for the molecular property, e.g., energy gap, of metal-organics compounds. Besides, we demonstrate that the adaptive machine learning workflow is an effective strategy to tackle the data deficiency issue in search of perovskite catalysts for the oxygen evolution reaction.
Advisors/Committee Members: Xin, Hongliang (committeechair), Achenie, Luke E. K. (committeechair), Deshmukh, Sanket A. (committee member), Morris, Amanda (committee member).
Subjects/Keywords: Computational catalysis; Density functional theory; Machine learning
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Li, Z. (2019). Accelerating Catalyst Discovery via Ab Initio Machine Learning. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/95915
Chicago Manual of Style (16th Edition):
Li, Zheng. “Accelerating Catalyst Discovery via Ab Initio Machine Learning.” 2019. Doctoral Dissertation, Virginia Tech. Accessed February 27, 2021.
http://hdl.handle.net/10919/95915.
MLA Handbook (7th Edition):
Li, Zheng. “Accelerating Catalyst Discovery via Ab Initio Machine Learning.” 2019. Web. 27 Feb 2021.
Vancouver:
Li Z. Accelerating Catalyst Discovery via Ab Initio Machine Learning. [Internet] [Doctoral dissertation]. Virginia Tech; 2019. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/10919/95915.
Council of Science Editors:
Li Z. Accelerating Catalyst Discovery via Ab Initio Machine Learning. [Doctoral Dissertation]. Virginia Tech; 2019. Available from: http://hdl.handle.net/10919/95915

University of New Mexico
22.
Johnson, Ryan.
Theoretical Studies of Transition Metal Catalysis.
Degree: Department of Chemistry and Chemical Biology, 2014, University of New Mexico
URL: https://digitalrepository.unm.edu/chem_etds/38
► Transition metal catalysis, being critical to nearly all aspects of the modern industrial world, is the focus of a series of theoretical studies which seek…
(more)
▼ Transition metal catalysis, being critical to nearly all aspects of the modern industrial world, is the focus of a series of theoretical studies which seek to elucidate the fundamental and electronic origins of enhanced chemical activity and selectivity. The application of
density functional theory on extended single metal and alloyed surfaces, supported single metal atoms, and gas phase cationic species illuminate various aspects of transition metal catalysis in a wide range of enviornments. Adsorption, reactivity, and other mechanistic details developed here suggest possible mechanisms used to aid interpretation of experimental results and guide developement of future catalysts.
Advisors/Committee Members: Guo, Hua, Datye, Abhaya, Grey, John, Qin, Yang.
Subjects/Keywords: Catalysis; Transition metals; Density functional theory
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Johnson, R. (2014). Theoretical Studies of Transition Metal Catalysis. (Doctoral Dissertation). University of New Mexico. Retrieved from https://digitalrepository.unm.edu/chem_etds/38
Chicago Manual of Style (16th Edition):
Johnson, Ryan. “Theoretical Studies of Transition Metal Catalysis.” 2014. Doctoral Dissertation, University of New Mexico. Accessed February 27, 2021.
https://digitalrepository.unm.edu/chem_etds/38.
MLA Handbook (7th Edition):
Johnson, Ryan. “Theoretical Studies of Transition Metal Catalysis.” 2014. Web. 27 Feb 2021.
Vancouver:
Johnson R. Theoretical Studies of Transition Metal Catalysis. [Internet] [Doctoral dissertation]. University of New Mexico; 2014. [cited 2021 Feb 27].
Available from: https://digitalrepository.unm.edu/chem_etds/38.
Council of Science Editors:
Johnson R. Theoretical Studies of Transition Metal Catalysis. [Doctoral Dissertation]. University of New Mexico; 2014. Available from: https://digitalrepository.unm.edu/chem_etds/38

University of Minnesota
23.
Marell, Daniel.
Understanding Organic Reaction Mechanisms Through Applications of Density-Functional Theory.
Degree: PhD, Chemistry, 2016, University of Minnesota
URL: http://hdl.handle.net/11299/182795
► The application of computational chemistry has a wide scope of utility. From large systems such as proteins or metal-organic frameworks down to the understanding of…
(more)
▼ The application of computational chemistry has a wide scope of utility. From large systems such as proteins or metal-organic frameworks down to the understanding of individual bonding patterns between atoms, there are endless opportunities to explore. Further utility is gained when the insights and resources of computational chemists can be applied to systems under investigation by experimental chemists The combined information of computational details with experimental findings can lead to new understanding of the systems being investigated. The ring-opening transesterification polymerization of caprolactone with an aluminum- salen catalyst is a useful reaction for the conversion of caprolactone to polyester. Mechanistic understanding of this reaction was gained through the interrogation of this process with density functional theory. Further, the origins for rate-enhancement through modification of electron-withdrawing groups was explained through the analysis of partial atomic charges. A rate enhancement observed by altering the backbone of the catalyst was also explained through the development of a distortion framework analysis. Rieske oxygenase are a class of protein that executes a variety of chemical reactions such as oxygenations, O- and N-demethylations, oxidations, and C–C bond formations en route to the formation of medically relevant natural products. The continued elucidation of the mechanism, including the characterization of reactive species was persued. Computational work to understand the impact partial atomic charge on the aromatic system (by inclusion of fluorine substituents) had on the rate constant demonstrated a clear correlation between the partial atomic charge on the C(2) position and the rate constant for a variety of substrates. A new reaction, the hexadehydro-Diels–Alder (HDDA) reaction takes a diyne and a diynophile to create a reactive benzyne intermediate. A series of six intramolecular HDDA substrates were found to undergo this transformation at relatively similar rates. Analysis of transition state geometries, investigation of both closed-shell and diradical mechanistic pathways, as well as insight from high-level calculations provide information about the nature of this intramolecular reaction. Extension of the mechanism led to predictive capability in good agreement with a new set of substrates as well.
Subjects/Keywords: density-functional theory; polymerization; reaction mechanism
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Marell, D. (2016). Understanding Organic Reaction Mechanisms Through Applications of Density-Functional Theory. (Doctoral Dissertation). University of Minnesota. Retrieved from http://hdl.handle.net/11299/182795
Chicago Manual of Style (16th Edition):
Marell, Daniel. “Understanding Organic Reaction Mechanisms Through Applications of Density-Functional Theory.” 2016. Doctoral Dissertation, University of Minnesota. Accessed February 27, 2021.
http://hdl.handle.net/11299/182795.
MLA Handbook (7th Edition):
Marell, Daniel. “Understanding Organic Reaction Mechanisms Through Applications of Density-Functional Theory.” 2016. Web. 27 Feb 2021.
Vancouver:
Marell D. Understanding Organic Reaction Mechanisms Through Applications of Density-Functional Theory. [Internet] [Doctoral dissertation]. University of Minnesota; 2016. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11299/182795.
Council of Science Editors:
Marell D. Understanding Organic Reaction Mechanisms Through Applications of Density-Functional Theory. [Doctoral Dissertation]. University of Minnesota; 2016. Available from: http://hdl.handle.net/11299/182795

Virginia Tech
24.
Fuhrer, Timothy J.
Computational Study of the Properties and Stabilities of Endohedral Metallofullerenes.
Degree: PhD, Chemistry, 2013, Virginia Tech
URL: http://hdl.handle.net/10919/19344
► The chemistry of fullerenes, which are a class of carbon allotropes that can be prepared by vaporization of graphite in an electric arc in a…
(more)
▼ The chemistry of fullerenes, which are a class of carbon allotropes that can be prepared by vaporization of graphite in an electric arc in a low pressure atmosphere,1 has become a topic of much experimental and theoretical study over the past 25 years. Herein we present a series of theoretical studies related to recently discovered or studied endohedral metallofullerenes (EMF) and a
theory as to the selective stability of certain isomers of EMFs. Computational treatments of the anions of C80 and C94 are presented and compared in an effort to gain an understanding and predictive model for which isomers of each cage size EMF will be most stable. A model is proposed in which the pentagons of fullerene anions are seen as charge localization centers that repel one another, making the pyracyclene bonding motif much more unstable for fullerene anions than for fullerene neutral cages. Computational treatments are also presented for two newly discovered EMFs,
[email protected] and
[email protected] [email protected] is reported to exhibit a previously undiscovered mode of internal cluster rotation, while
[email protected] is shown to have unusual stability for an azofullerene with a large spin quantum number (15/2). Finally, computational techniques are employed to predict the thermodynamic feasibility of a chemical reaction replacing one metal atom in a trimetallic-nitride template (TNT) endohedral metallofullerene with different metal atom. At least two of these are predicted to be thermodynamically practical.
Advisors/Committee Members: Dorn, Harry C. (committeechair), Tanko, James M. (committee member), Madsen, Louis A. (committee member), Crawford, T. Daniel (committee member), Valeyev, Eduard Faritovich (committee member).
Subjects/Keywords: Fullerenes; Endohedral; Metallofullerenes; Density Functional Theory
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Manager
APA (6th Edition):
Fuhrer, T. J. (2013). Computational Study of the Properties and Stabilities of Endohedral Metallofullerenes. (Doctoral Dissertation). Virginia Tech. Retrieved from http://hdl.handle.net/10919/19344
Chicago Manual of Style (16th Edition):
Fuhrer, Timothy J. “Computational Study of the Properties and Stabilities of Endohedral Metallofullerenes.” 2013. Doctoral Dissertation, Virginia Tech. Accessed February 27, 2021.
http://hdl.handle.net/10919/19344.
MLA Handbook (7th Edition):
Fuhrer, Timothy J. “Computational Study of the Properties and Stabilities of Endohedral Metallofullerenes.” 2013. Web. 27 Feb 2021.
Vancouver:
Fuhrer TJ. Computational Study of the Properties and Stabilities of Endohedral Metallofullerenes. [Internet] [Doctoral dissertation]. Virginia Tech; 2013. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/10919/19344.
Council of Science Editors:
Fuhrer TJ. Computational Study of the Properties and Stabilities of Endohedral Metallofullerenes. [Doctoral Dissertation]. Virginia Tech; 2013. Available from: http://hdl.handle.net/10919/19344

Virginia Tech
25.
Li, Zheng.
Assessing Structure–Property Relationships of Crystal Materials using Deep Learning.
Degree: MS, Computer Science and Applications, 2020, Virginia Tech
URL: http://hdl.handle.net/10919/99488
► Machine learning technologies, particularly deep learning, have demonstrated remarkable progress in facilitating the high-throughput materials discovery process. In essence, machine learning algorithms have the ability…
(more)
▼ Machine learning technologies, particularly deep learning, have demonstrated remarkable progress in facilitating the high-throughput materials discovery process. In essence, machine learning algorithms have the ability to uncover the hidden patterns of data and make appropriate decisions without being explicitly programmed. Nevertheless, implementing machine learning models in the field of material design remains a challenging task. One of the biggest limitations is our insufficient knowledge about the structure-property relationships for material systems. As the performance of machine learning models is to a large degree determined by the underlying material representation method, which typically requires the experts to have in-depth knowledge of the material systems. Thus, designing effective feature representation methods is always the most crucial aspect for machine learning model development and the process takes a significant amount of manual effort. Even though tremendous efforts have been made in recent years, the research process for robust feature representation methods is still slow. In this regard, we attempt to automate the feature engineering process with the assistance of advanced deep learning algorithms. Unlike the conventional machine learning models, our deep learning models (i.e., convolutional neural networks, graph neural networks) are capable of processing massive amounts of structured data such as spectrum and crystal graphs. Specifically, the deep learning models are explicitly designed to learn the hidden latent variables that are contained in crystal structures in an automatic fashion and provide accurate prediction results. We believe the deep learning models have huge potential to simplify the machine learning modeling process and facilitate the discovery of promising
functional materials.
Advisors/Committee Members: Karpatne, Anuj (committeechair), Xin, Hongliang (committee member), Viswanath, Bimal (committee member).
Subjects/Keywords: Density functional theory; Material design; Machine learning
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Li, Z. (2020). Assessing Structure–Property Relationships of Crystal Materials using Deep Learning. (Masters Thesis). Virginia Tech. Retrieved from http://hdl.handle.net/10919/99488
Chicago Manual of Style (16th Edition):
Li, Zheng. “Assessing Structure–Property Relationships of Crystal Materials using Deep Learning.” 2020. Masters Thesis, Virginia Tech. Accessed February 27, 2021.
http://hdl.handle.net/10919/99488.
MLA Handbook (7th Edition):
Li, Zheng. “Assessing Structure–Property Relationships of Crystal Materials using Deep Learning.” 2020. Web. 27 Feb 2021.
Vancouver:
Li Z. Assessing Structure–Property Relationships of Crystal Materials using Deep Learning. [Internet] [Masters thesis]. Virginia Tech; 2020. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/10919/99488.
Council of Science Editors:
Li Z. Assessing Structure–Property Relationships of Crystal Materials using Deep Learning. [Masters Thesis]. Virginia Tech; 2020. Available from: http://hdl.handle.net/10919/99488

University of Texas – Austin
26.
Li, Xinyu, Ph. D.
Computational investigation of functional perovskites.
Degree: PhD, Materials Science & Engineering, 2018, University of Texas – Austin
URL: http://hdl.handle.net/2152/67995
► Functional perovskites have been investigated extensively for many years. Thousands of new perovskites are synthesized and studied every year. Many functional perovskites have been widely…
(more)
▼ Functional perovskites have been investigated extensively for many years.
Thousands of new perovskites are synthesized and studied every year. Many
functional
perovskites have been widely employed in industry.
Density functional theory (DFT)
calculations have been used to obtain a better understanding of
functional perovskites,
especially their electronic and structural properties. During my graduate study, I
investigated perovskite’s properties on ionic transport, magnetic ordering,
ferroelectricity, physical property and phase transition using DFT calculations.
In the first case, I simulated the ionic transport process in several Ruddlesden-
Popper (RP) phases. Climbing image nudged elastic band (CI-NEB) calculation was used
to get accurate oxygen interstitial migration barrier. I established a linkage between
interstitial migration barrier and perovskite’s octahedral rotation with symmetry mode
approach. Two factors, including A-site atom radius and epitaxial strain, were used to
reduce interstitial migration barrier in my simulation. My study on ionic transport in RP
phases provides guidance on the design of fast ionic transport in perovskite oxides.
In the second case, DFT calculation was employed to investigate a double
perovskite’s magnetic and electronic properties. A new ferroelectric mechanism in
perovskite, associated with the displacement of coplanar Mn²⁺, was discovered
experimentally. My DFT calculation explained the origin of coplanar displacement from
an orbital point of view. In addition, DFT simulations were used in the design of
ferroelectricity enhancement perovskite.
In the last case, I simulated structural behaviors under pressure of several double
perovskites. The results show that these double perovskites can be divided into two
groups based on their octahedral rotations under pressure. The origin of their distinct
volume reduction mechanisms was studied through DFT simulations. The difference
between the two mechanisms and their influence on bulk modulus were discussed based
on my computational results.
Advisors/Committee Members: Henkelman, Graeme (advisor), Zhou, Jianshi (advisor), Goodenough, John (committee member), Hwang, Gyeong (committee member).
Subjects/Keywords: First-principle calculation; Density functional theory; Perovskite
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APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Li, Xinyu, P. D. (2018). Computational investigation of functional perovskites. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/67995
Chicago Manual of Style (16th Edition):
Li, Xinyu, Ph D. “Computational investigation of functional perovskites.” 2018. Doctoral Dissertation, University of Texas – Austin. Accessed February 27, 2021.
http://hdl.handle.net/2152/67995.
MLA Handbook (7th Edition):
Li, Xinyu, Ph D. “Computational investigation of functional perovskites.” 2018. Web. 27 Feb 2021.
Vancouver:
Li, Xinyu PD. Computational investigation of functional perovskites. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2018. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/2152/67995.
Council of Science Editors:
Li, Xinyu PD. Computational investigation of functional perovskites. [Doctoral Dissertation]. University of Texas – Austin; 2018. Available from: http://hdl.handle.net/2152/67995

University of Texas – Austin
27.
Li, Hao, Ph. D.
Catalytic reactions at alloy surfaces.
Degree: PhD, Chemistry, 2020, University of Texas – Austin
URL: http://dx.doi.org/10.26153/tsw/8356
► Alloys have been widely studied for heterogeneous catalysis. Many bi- and multi-metallic alloys have enhanced performance as compared to their monometallic counterparts. However, a full…
(more)
▼ Alloys have been widely studied for heterogeneous catalysis. Many bi- and multi-metallic alloys have enhanced performance as compared to their monometallic counterparts. However, a full understanding of the alloying effects was not well-established. In my Ph.D. works,
density functional theory (DFT) was employed to disentangle the atomic ensemble, ligand, and strain effects of surfaces alloyed by transition metals. It is found that alloying elements with strong and weak adsorption properties could produce a surface ensemble with optimally tuned adsorbate binding, which can help to understand the mechanisms of catalytic reactions and design high-performance alloy catalysts. We developed a Tunability
theory that quantifies the tuning of adsorbate bindings at the specific atomic ensembles on surface, which provides predictive power of
theory for experiments. Using combined theoretical and experimental methods, we designed and studied new alloy catalysts for many industrially significant reactions including electrocatalysis, vapor-phase catalysis, and liquid-phase catalysis. We developed comprehensive theories that predominantly based on the atomic ensemble effect to unify theories and experiments for alloy heterogeneous catalysts. Most importantly, we show how fundamental understandings from theories can be precisely applied to efficient energy and environmental reactions. In addition, to accelerate atomistic simulations and materials design, we have been developing a machine learning framework that can fit the potential energy surfaces from the quantum mechanical data, which can help to partly replace expensive DFT calculations and reduce scientific costs
Advisors/Committee Members: Henkelman, Graeme (advisor), Mullins, Charles B (committee member), Hwang, Gyeong (committee member), Humphrey, Simon (committee member).
Subjects/Keywords: Catalysis; Alloy; Density functional theory; Catalytic modeling
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Li, Hao, P. D. (2020). Catalytic reactions at alloy surfaces. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://dx.doi.org/10.26153/tsw/8356
Chicago Manual of Style (16th Edition):
Li, Hao, Ph D. “Catalytic reactions at alloy surfaces.” 2020. Doctoral Dissertation, University of Texas – Austin. Accessed February 27, 2021.
http://dx.doi.org/10.26153/tsw/8356.
MLA Handbook (7th Edition):
Li, Hao, Ph D. “Catalytic reactions at alloy surfaces.” 2020. Web. 27 Feb 2021.
Vancouver:
Li, Hao PD. Catalytic reactions at alloy surfaces. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2020. [cited 2021 Feb 27].
Available from: http://dx.doi.org/10.26153/tsw/8356.
Council of Science Editors:
Li, Hao PD. Catalytic reactions at alloy surfaces. [Doctoral Dissertation]. University of Texas – Austin; 2020. Available from: http://dx.doi.org/10.26153/tsw/8356

University of Texas – Austin
28.
-6008-5857.
Advanced modeling for end-of-the-roadmap CMOS and potential beyond-CMOS applications.
Degree: PhD, Electrical and Computer engineering, 2016, University of Texas – Austin
URL: http://hdl.handle.net/2152/40264
► End-of-the-roadmap CMOS devices are explored via particle-based ensemble semi-classical Monte Carlo (MC) methods employing quantum corrections (QCs) to address quantum confinement and degenerate carrier populations.…
(more)
▼ End-of-the-roadmap CMOS devices are explored via particle-based ensemble semi-classical Monte Carlo (MC) methods employing quantum corrections (QCs) to address quantum confinement and degenerate carrier populations. The significance of such QCs is illustrated through simulation of n-channel III-V and Si FinFETs. Original contributions include our treatment of far-from-equilibrium degenerate statistics and QC-based modeling of surface-roughness scattering, as well as considering quantum-confined phonon and ionized-impurity scattering in 3D. Typical MC simulations approximate degenerate carrier populations as Fermi distributions to model the Pauli-blocking (PB) of scattering to occupied final states. To allow for increasingly far-from-equilibrium non-Fermi carrier distributions in ultra-scaled and III-V devices, we instead generate the final-state occupation probabilities used for PB by sampling the local carrier populations as a function of energy and energy valley. This process is aided by the use of fractional carriers or sub-carriers, which minimizes classical carrier-carrier scattering. Quantum confinement effects are addressed through quantum-correction potentials (QCPs) generated from coupled Schrödinger-Poisson solvers, as commonly done. However, we use our valley- and orientation-dependent QCPs not just to redistribute carriers in real space, or even among energy valleys, but also to calculate confinement-dependent phonon, ionized-impurity, and surface-roughness scattering rates. Collectively, these quantum effects can substantially reduce and even eliminate otherwise expected benefits of considered InGaAs FinFETs over otherwise identical Si FinFETs, despite higher thermal velocities in InGaAs. Beyond-CMOS device concepts are also being considered for future applications. Thin-film sub-5 nm magnetic skyrmions constitute an ultimate scaling alternative for beyond-CMOS data storage technologies. These robust non-collinear spin-textures can be moved and manipulated by spin-polarized or non-spin-polarized electrical currents, which is extremely attractive for integration with current memory technologies. An innovative technique to detect isolated nano-skyrmions with a current-perpendicular-to-plane is shown, which has immediate implications for device concepts. Such a mechanism is explored by studying the atomistic electronic structure of the magnetic quasiparticles. The tunneling conductance is quite sensitive to spatial variations in the electronic structure, as a large atomistic conductance anisotropy up to 20 is found for magnetic skyrmions in Pd/Fe/Ir(111) magnetic thin-films. This spin-mixing magnetoresistance effect possibly could be incorporated in future magnetic storage technologies.
Advisors/Committee Members: Register, Leonard F. (advisor), Banerjee, Sanjay K (committee member), Tutuc, Emanuel (committee member), Lee, Jack C (committee member), MacDonald, Allan H (committee member).
Subjects/Keywords: FinFETs; Skyrmions; Monte Carlo; Density-functional theory
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
-6008-5857. (2016). Advanced modeling for end-of-the-roadmap CMOS and potential beyond-CMOS applications. (Doctoral Dissertation). University of Texas – Austin. Retrieved from http://hdl.handle.net/2152/40264
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Chicago Manual of Style (16th Edition):
-6008-5857. “Advanced modeling for end-of-the-roadmap CMOS and potential beyond-CMOS applications.” 2016. Doctoral Dissertation, University of Texas – Austin. Accessed February 27, 2021.
http://hdl.handle.net/2152/40264.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
MLA Handbook (7th Edition):
-6008-5857. “Advanced modeling for end-of-the-roadmap CMOS and potential beyond-CMOS applications.” 2016. Web. 27 Feb 2021.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Vancouver:
-6008-5857. Advanced modeling for end-of-the-roadmap CMOS and potential beyond-CMOS applications. [Internet] [Doctoral dissertation]. University of Texas – Austin; 2016. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/2152/40264.
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete
Council of Science Editors:
-6008-5857. Advanced modeling for end-of-the-roadmap CMOS and potential beyond-CMOS applications. [Doctoral Dissertation]. University of Texas – Austin; 2016. Available from: http://hdl.handle.net/2152/40264
Note: this citation may be lacking information needed for this citation format:
Author name may be incomplete

University of Oklahoma
29.
Mou, Tong.
Thermocatalytic and Plasmonic Catalytic Hydrogenation Reactions from First Principles.
Degree: PhD, 2020, University of Oklahoma
URL: http://hdl.handle.net/11244/324960
► As the world is facing post-climate change situation and the escalating demand of energy, a gradual energy transition from fossil fuels (oil, coal, natural gas)…
(more)
▼ As the world is facing post-climate change situation and the escalating demand of energy, a gradual energy transition from fossil fuels (oil, coal, natural gas) to renewable energy technologies (natural resources such as biomass, solar, wind) is inevitable and essential. Solar energy, as the most abundant, safe and clean energy source among all available renewable energy technologies, has prospective potentials as future power generators. However, although significant progress has been made, the electricity generation from sunlight in commercial photovoltaic (PV) solar cells still suffer from low energy conversion efficiency and high cost. In addition, due to technological difficulties associated with the rapid electron-hole recombination in photocatalysis systems, realizing commercial implementations of photocatalytic systems remains a challenge.
In this dissertation, a thorough first-principles analysis was performed on three hydrogen-involving processes, including solar to electricity, catalytic hydrotreating and solar to chemical conversion processes. By investigating their thermodynamic and kinetics properties, we aim to bridge solar energy utilization with chemical energy production under ambient conditions.
We begin with the discussion of nitrogen-related defects in a dilute nitride material GaInNAs, which shows promising candidacy as the fourth junction in multijunction solar cells. While the photoluminescence spectra presented remaining defects in the hydrogenated alloy, first-principles calculations revealed the thermodynamic limitation of hydrogen addition on the In-N complexes. Next, a comprehensive kinetic study on cyclohexene hydrogenation reaction on palladium and palladium hydride surfaces were conducted, through a combination of experimental and theoretical work, which laid foundations for later study of plasmonic hydrogenation reactions. In light of thermodynamic and kinetic studies addressed earlier, we undertake investigations on plasmonic catalytic hydrogenation of 4-nitrophenol on gold surfaces. We measured the catalytic activity with and without light irradiation and observed higher reaction rates under light. A theoretical correlation between rate enhancements and reaction energy barrier reduction was constructed via
density functional theory calculations. Moreover, we propose that the reaction can be further enhanced over a hexagonal boron nitride (h-BN) layer supported on Au in an
[email protected] core-shell structure. In this dissertation, we attempt to understand the electron behavior at atomic level, through the investigation of hydrogen-involved processes. Moreover, by discussing efficiency improvement options, we attempt to guide the future design of plasmonic catalysts.
Advisors/Committee Members: Wang, Bin (advisor), Sellers, Ian (committee member), Resasco, Daniel (committee member), Huang, Liangliang (committee member), Walters, Keisha (committee member).
Subjects/Keywords: Density Functional Theory; hydrogenation; plasmonic catalysis
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Mou, T. (2020). Thermocatalytic and Plasmonic Catalytic Hydrogenation Reactions from First Principles. (Doctoral Dissertation). University of Oklahoma. Retrieved from http://hdl.handle.net/11244/324960
Chicago Manual of Style (16th Edition):
Mou, Tong. “Thermocatalytic and Plasmonic Catalytic Hydrogenation Reactions from First Principles.” 2020. Doctoral Dissertation, University of Oklahoma. Accessed February 27, 2021.
http://hdl.handle.net/11244/324960.
MLA Handbook (7th Edition):
Mou, Tong. “Thermocatalytic and Plasmonic Catalytic Hydrogenation Reactions from First Principles.” 2020. Web. 27 Feb 2021.
Vancouver:
Mou T. Thermocatalytic and Plasmonic Catalytic Hydrogenation Reactions from First Principles. [Internet] [Doctoral dissertation]. University of Oklahoma; 2020. [cited 2021 Feb 27].
Available from: http://hdl.handle.net/11244/324960.
Council of Science Editors:
Mou T. Thermocatalytic and Plasmonic Catalytic Hydrogenation Reactions from First Principles. [Doctoral Dissertation]. University of Oklahoma; 2020. Available from: http://hdl.handle.net/11244/324960

University of Toledo
30.
Shi, Tingting.
Optoelectronic and Defect Properties in Earth Abundant
Photovoltaic Materials: First-principle Calculations.
Degree: PhD, College of Natural Sciences and
Mathematics, 2014, University of Toledo
URL: http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418391935
► In this dissertation, a series of earth-abundant photovoltaic materials including lead halide perovskites, copper based compounds, and silicon are investigated via density functional theory (DFT).…
(more)
▼ In this dissertation, a series of earth-abundant
photovoltaic materials including lead halide perovskites, copper
based compounds, and silicon are investigated via
density
functional theory (DFT). Firstly, we study the unique
optoelectronic properties of perovskite CH3NH3PbI3 and CH3NH3PbBr3.
First-principle calculations show that CH3NH3PbI3 perovskite solar
cells exhibit remarkable optoelectronic properties that account for
the high open circuit voltage (Voc) and long electron-hole
diffusion lengths. Our results reveal that for intrinsic doping,
dominant point defects produce only shallow levels. Therefore lead
halide perovskites are expected to exhibit intrinsic low
non-radiative recombination rates. The conductivity of perovskites
can be tuned from p-type to n-type by controlling the growth
conditions. For extrinsic defects, the p-type perovskites can be
achieved by doping group-IA, -IB, or -VIA elements, such as Na, K,
Rb, Cu, and O at I-rich growth conditions. We further show that
despite a large band gap of 2.2 eV, the dominant defects in
CH3NH3PbBr3 also create only shallow levels. The photovoltaic
properties of CH3NH3PbBr3–based perovskite absorbers can be tuned
via defect engineering. Highly conductive p-type CH3NH3PbBr3 can be
synthesized under Br-rich growth conditions. Such CH3NH3PbBr3 may
be potential low-cost hole transporting materials for lead halide
perovskite solar cells. All these unique defect properties of
perovskites are largely due to the strong Pb lone-pair s orbital
and I p (Br p) orbital antibonding coupling and the high ionicity
of CH3NH3PbX3 (X=I, Br). Secondly, we study the optoelectronic
properties of Cu-V-VI earth abundant compounds. These low cost thin
films may have the good electronic and optical properties. We have
studied the structural, electronic and optical properties of
Cu3-V-VI4 compounds. After testing four different crystal
structures, enargite, wurtzite-PMCA, famatinite and
zinc-blend-PMCA, we find that Cu3PS4 and Cu3PSe4 prefer
energetically the enargite structure, whereas, other compounds
favor the famatinite structure. Among the compounds and structures
considered, enargite Cu3PSe4, and famatinite Cu3AsS4, are suitable
for single junction solar cell applications due to bandgaps of 1.32
eV and 1.15 eV, respectively. Furthermore, CuSbS2 are also studied
by
density functional theory and HSE06 hybrid
functional. The
chalcostibite CuSbS2 has an indirect band gap of 1.85 eV, whereas
the chalcogenide Cu3SbS4 has a direct band gap of 0.89 eV. We find
that the large difference on band gaps is mainly attributed to the
different Sb charge states. We further predict that the Sb charge
states will affect the defect physics. Particularly, the Sb lone
pair s orbitals in CuSbS2 have strong influence on the formation
energies of Sb-related defects. Lastly, we have studied the atomic
structure and electronic properties of aluminum (Al)-related defect
complexes in silicon. We find a unique stable complex configuration
consisting of an Ali and an oxygen dimer, Ali-2Oi, which introduces
deep…
Advisors/Committee Members: Yan, Yanfa (Advisor).
Subjects/Keywords: Physics; Perovskites solar cell, Density functional
theory
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❌
APA ·
Chicago ·
MLA ·
Vancouver ·
CSE |
Export
to Zotero / EndNote / Reference
Manager
APA (6th Edition):
Shi, T. (2014). Optoelectronic and Defect Properties in Earth Abundant
Photovoltaic Materials: First-principle Calculations. (Doctoral Dissertation). University of Toledo. Retrieved from http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418391935
Chicago Manual of Style (16th Edition):
Shi, Tingting. “Optoelectronic and Defect Properties in Earth Abundant
Photovoltaic Materials: First-principle Calculations.” 2014. Doctoral Dissertation, University of Toledo. Accessed February 27, 2021.
http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418391935.
MLA Handbook (7th Edition):
Shi, Tingting. “Optoelectronic and Defect Properties in Earth Abundant
Photovoltaic Materials: First-principle Calculations.” 2014. Web. 27 Feb 2021.
Vancouver:
Shi T. Optoelectronic and Defect Properties in Earth Abundant
Photovoltaic Materials: First-principle Calculations. [Internet] [Doctoral dissertation]. University of Toledo; 2014. [cited 2021 Feb 27].
Available from: http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418391935.
Council of Science Editors:
Shi T. Optoelectronic and Defect Properties in Earth Abundant
Photovoltaic Materials: First-principle Calculations. [Doctoral Dissertation]. University of Toledo; 2014. Available from: http://rave.ohiolink.edu/etdc/view?acc_num=toledo1418391935
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