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dc.contributor.advisor Scuseria, Gustavo E.
dc.contributor.advisor Ernzerhof, Matthias
dc.creatorMaximoff, Sergey N.
dc.date.accessioned 2018-12-03T18:32:54Z
dc.date.available 2018-12-03T18:32:54Z
dc.date.issued 2006
dc.identifier.urihttps://hdl.handle.net/1911/103708
dc.description.abstract This thesis is about current-density functional theory. Current plays a role in three important types of physical systems: molecular electronic devices (MED), broken current-symmetry states of atoms and molecules, and states of atoms and molecules in external magnetic fields. Developments in these three areas of current-density functional theory are presented in this thesis. First, the thesis proposes an extension of conventional density functional theory that accounts for the direct current flow through a MED under a voltage bias. The irreversible current flow in a MED is introduced by coupling the MED to a pair of reservoirs at two distinct local equilibria. This coupling defines a model non-Hermitian Hamiltonian whose eigenfunctions correspond to the coherent current carrying modes of the MED. A stationarity principle for the irreversible state of MED is constructed that resembles the variational principle of conventional quantum mechanics. As an application of the stationarity principle, a generalization of Kohn-Sham density functional theory suitable for MEDs is derived. The developed current density functional theory is applied to a di-thiol benzene molecule under a voltage bias. The new approach agrees with the established non-equilibrium Green's functions method. Second, this thesis develops an approximate functional that accounts for the current dependence of the exchange-correlation energy in systems with broken current symmetry. Starting from the Perdew-Burke-Ernzerhof generalized gradient approximation, first principle conditions are employed to built a non-empirical exchange functional. Matching the correlation functional to that for exchange yields a current-dependent approximation for correlation. The resulting functional is given in a simple closed form. The benchmark of this functional against the broken current symmetry ground-states of open shell atoms indicates an improvement, as compared to the current-independent generalized gradient approximations. Third, this thesis presents a current-dependent approach to magnetic response properties of atoms and molecules. The NMR shielding tensors computed for a benchmark set of molecules indicate a superiority of the novel approach over the common generalized gradient approximations and hybrid functionals for strongly deshielded nuclei.
dc.format.extent 67 pp
dc.language.iso eng
dc.subjectChemistry
Molecules
Pure sciences
Conductivity
Current density
Molecular electronics
dc.title Density functional theory of molecular conductivity
dc.identifier.digital 305274876
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Chemistry
thesis.degree.discipline Natural Sciences
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy
dc.identifier.callno THESIS CHEM. 2007 MAXIMOFF
dc.identifier.citation Maximoff, Sergey N.. "Density functional theory of molecular conductivity." (2006) Diss., Rice University. https://hdl.handle.net/1911/103708.


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