Advanced search options

Advanced Search Options 🞨

Browse by author name (“Author name starts with…”).

Find ETDs with:

in
/  
in
/  
in
/  
in

Written in Published in Earliest date Latest date

Sorted by

Results per page:

You searched for id:"handle:11375/22016". One record found.

Search Limiters

Last 2 Years | English Only

No search limiters apply to these results.

▼ Search Limiters


McMaster University

1. Heidar-Zadeh, Farnaz. Variational Information-Theoretic Atoms-in-Molecules.

Degree: PhD, 2017, McMaster University

It is common to use the electron density to partition a molecular system into atomic regions. The necessity for such a partitioning scheme is rooted in the unquestionable role of atoms in chemistry. Nevertheless, atomic properties are not well- defined concepts within the domain of quantum mechanics, as they are not observable. This has resulted in a proliferation of different approaches to retrieve the concept of atoms in molecules (AIM) within the domain of quantum mechanics and in silico experiments based on various flavors of model theories. One of the most popular families of models is the Hirshfeld, or stockholder, partitioning methods. Hirshfeld methods do not produce sharp atomic boundaries, but instead distribute the molecular electron density at each point between all the nuclear centers constituting the molecule. The various flavors of the Hirshfeld scheme differ mainly in how the atomic shares are computed from a reference promolecular density and how the reference promolecular density is defined. We first establish the pervasiveness of the Hirshfeld portioning by extending its information-theoretic framework. This characterizes the family of f-divergence measures as necessary and sufficient for deriving Hirshfeld scheme. Then, we developed a variational version of Hirshfeld partitioning method, called Additive Variational Hirshfeld (AVH). The key idea is finding the promolecular density, expanded as a linear combination of charged and neutral spherically-averaged isolated atomic densities in their ground and/or excited states, that resembles the molecular density as much as possible. Using Kullback-Liebler divergence measure, this automatically guarantees that each atom and proatom have the same number of electrons, and that the partitioning is size consistent. The robustness of this method is confirmed by testing it on various datasets. Considering the mathematical properties and our numerical results, we believe that AVH has the potential to supplant other Hirshfeld partitioning schemes in future.

Thesis

Doctor of Philosophy (PhD)

Advisors/Committee Members: Ayers, Paul Woodson, Bultinck, Patrick, Verstraelen, Toon, Chemistry.

Subjects/Keywords: Atoms in Molecules; Stockholder Partitioning; Additive Variational Hirshfeld; Information-theory measures; Kullback-Liebler divergence

Record DetailsSimilar RecordsGoogle PlusoneFacebookTwitterCiteULikeMendeleyreddit

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

APA (6th Edition):

Heidar-Zadeh, F. (2017). Variational Information-Theoretic Atoms-in-Molecules. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/22016

Chicago Manual of Style (16th Edition):

Heidar-Zadeh, Farnaz. “Variational Information-Theoretic Atoms-in-Molecules.” 2017. Doctoral Dissertation, McMaster University. Accessed December 18, 2017. http://hdl.handle.net/11375/22016.

MLA Handbook (7th Edition):

Heidar-Zadeh, Farnaz. “Variational Information-Theoretic Atoms-in-Molecules.” 2017. Web. 18 Dec 2017.

Vancouver:

Heidar-Zadeh F. Variational Information-Theoretic Atoms-in-Molecules. [Internet] [Doctoral dissertation]. McMaster University; 2017. [cited 2017 Dec 18]. Available from: http://hdl.handle.net/11375/22016.

Council of Science Editors:

Heidar-Zadeh F. Variational Information-Theoretic Atoms-in-Molecules. [Doctoral Dissertation]. McMaster University; 2017. Available from: http://hdl.handle.net/11375/22016

.