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For properties of interacting electron systems, Kohn-Sham (KS) theory is often favored over many-body perturbation theory (MBPT) owing to its low computational cost. However, the exact KS potential can be challenging to approximate, for…

Materials Science · Physics 2021-01-15 Jack Wetherell , Matthew Hodgson , Leopold Talirz , Rex Godby

In contrast to the original Kohn-Sham (KS) formalism, we propose a density functional theory (DFT) with fractional orbital occupations for the study of ground states of many-electron systems, wherein strong static correlation is shown to be…

Chemical Physics · Physics 2015-06-03 Jeng-Da Chai

Given the time-evolution of an electron charge density, the local potential in Kohn-Sham time-dependent density functional theory (KS-TDDFT) can be modeled as a sum of instantaneous and dynamic contributions by assuming a certain form of…

Computational Physics · Physics 2016-11-09 R. J. Magyar

Exact density-functional theory is reconstructed here from its convex variational structure as two parallel exact ensemble hierarchies: an interacting hierarchy rooted in Lieb's ensemble formulation and a noninteracting hierarchy rooted in…

Chemical Physics · Physics 2026-05-01 Nan Sheng

By propagating the many-body Schr\"odinger equation, we determine the exact time-dependent Kohn-Sham potential for a system of strongly correlated electrons which undergo field-induced tunneling. Numerous features are entirely absent from…

Strongly Correlated Electrons · Physics 2021-01-15 Matthew J. P. Hodgson , James D. Ramsden , Jacob B. J. Chapman , Piers Lillystone , Rex W Godby

Gross--Oliveira--Kohn (GOK) ensemble density-functional theory (GOK-DFT) is a time-\textit{independent} extension of density-functional theory (DFT) which allows to compute excited-state energies via the derivatives of the ensemble energy…

Chemical Physics · Physics 2020-06-18 Clotilde Marut , Bruno Senjean , Emmanuel Fromager , Pierre-François Loos

There are several approximations to the exchange-correlation functional in density-functional theory that accurately predict total energy-related properties of many-electron systems, such as binding energies, bond lengths, and crystal…

Chemical Physics · Physics 2015-09-30 Eli Kraisler , Tobias Schmidt , Stephan Kümmel , Leeor Kronik

Density functional theory is currently the most widely applied method in electronic structure theory. The Kohn-Sham method, based on a fictitious system of non-interacting particles, is the work horse of the theory. The particular form of…

Chemical Physics · Physics 2016-06-01 Hubertus J J van Dam

Fromager and Lasorne [Electron. Struct. 6 025002 (2024)] have recently derived an in-principle exact Kohn-Sham density functional theory (KS-DFT) of electrons and nuclei, where the nuclear density and the (so-called conditional) electronic…

Chemical Physics · Physics 2026-03-10 Lucien Dupuy , Benjamin Lasorne , Emmanuel Fromager

This article generalizes the notion of the local density of a many-body system to introduce collective coordinates as explicit degrees of freedom. It is shown that the energy of the system can be expressed as a functional of this object.…

Nuclear Theory · Physics 2014-04-23 Thomas Lesinski

The recently developed hypercomplex Kohn-Sham (HCKS) theory shows great potential to overcome the static/strong correlation issue in density functional theory (DFT), which highlights the necessity of further exploration of the HCKS theory…

Chemical Physics · Physics 2022-03-16 Neil Qiang Su

A framework for developing new approximate electronic structure methods is presented, in which the correlation energy of a many-electron system in the ground state is computed as in the single-reference second-order many-body perturbation…

Chemical Physics · Physics 2011-06-15 Dimitri Laikov

An interesting fundamental problem in density-functional theory of electronic structure of matter is to construct the exact Kohn-Sham (KS) potential for a given density. The exact potential can then be used to assess the accuracy of…

Atomic and Molecular Clusters · Physics 2019-05-22 Ashish Kumar , Rabeet Singh , Manoj K. Harbola

This paper derives and demonstrates a new, purely density-based ab initio approach for calculation of the energies and properties of many-electron systems. It is based upon the discovery of relationships that govern the "mechanics" of the…

Chemical Physics · Physics 2024-09-04 James C. Ellenbogen

In the exact Kohn-Sham density-functional theory (DFT), the total energy versus the number of electrons is a series of linear segments between integer points. However, commonly used approximate density functionals produce total energies…

Materials Science · Physics 2013-04-03 Eli Kraisler , Leeor Kronik

Kohn-Sham spin-density functional theory provides an efficient and accurate model to study electron-electron interaction effects in quantum dots, but its application to large systems is a challenge. An efficient algorithm for the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hong Jiang , Harold U. Baranger , Weitao Yang

As density functional theory conventionally assumes that the density of a chosen model system (e.g., the Kohn-Sham system) is the same as the exact one, one might expect that approximations to the exact density introduce supplementary…

Chemical Physics · Physics 2009-02-17 A. Savin

We analytically construct the wave function that, for a given initial state, produces a prescribed density for a quantum ring with two non-interacting particles in a singlet state. In this case the initial state is completely determined by…

Strongly Correlated Electrons · Physics 2013-08-23 M. Ruggenthaler , S. E. B. Nielsen , R. van Leeuwen

Kohn-Sham (KS) formalism of Density Functional Theory is modified to include the systems with strong non-dynamic electron correlation. Unlike in extended KS and broken symmetry unrestricted KS formalisms, cases of both singlet-triplet and…

Chemical Physics · Physics 2007-05-23 Artem Masunov

A new method for extracting ensemble Kohn-Sham potentials from accurate excited state densities is applied to a variety of two electron systems, exploring the behavior of exact ensemble density functional theory. The issue of separating the…