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Related papers: Exact and approximate Kohn-Sham potentials in ense…

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Exchange-correlation potentials vxc and energy densities exc are derived for integer and fractional electron counts using an orbital-averaged Kohn-Sham inversion procedure. The reference densities for inversion come from full configuration…

Chemical Physics · Physics 2025-04-30 Vaibhav Khanna , Bikash Kanungo , Jeffrey Hatch , Joshua Kammeraad , Paul M. Zimmerman

We review and expand on our work to impose constraints on the effective Kohn Sham (KS) potential of local and semi-local density functional approximations. In this work, we relax a previously imposed positivity constraint, which increased…

Modern density functional theory (DFT) calculations employ the Kohn-Sham (KS) system of non-interacting electrons as a reference, with all complications buried in the exchange-correlation energy (Exc). The adiabatic connection formula gives…

Other Condensed Matter · Physics 2009-10-02 Zhenfei Liu , Kieron Burke

We present analytic expressions for the exact density functional and Kohn-Sham Hamiltonian of simple tight-binding models of correlated electrons. These are the single- and double-site versions of the Anderson, Hubbard and spinless fermion…

Strongly Correlated Electrons · Physics 2012-01-16 D. J. Carrascal , J. Ferrer

The exchange-correlation potential experienced by an electron in the free space adjacent to a solid surface or to a low-dimensional system defines the fundamental image states and is generally important in surface- and nano-science. Here we…

Mesoscale and Nanoscale Physics · Physics 2016-06-01 V. U. Nazarov

The random phase approximation (RPA) for the electron correlation energy, combined with the exact-exchange energy, represents the state-of-the-art exchange-correlation functional within density-functional theory (DFT). However, the standard…

Other Condensed Matter · Physics 2015-05-20 Xinguo Ren , Patrick Rinke , Alexandre Tkatchenko , Matthias Scheffler

Exact-exchange self-consistent calculations of the Kohn-Sham potential, surface energy, and work function of jellium slabs are reported in the framework of the Optimized Effective Potential (OEP) scheme of Density Functional Theory. In the…

Other Condensed Matter · Physics 2009-11-13 C. M. Horowitz , C. R. Proetto , J. M. Pitarke

The recent use of a new ensemble in density functional theory (DFT) to yield direct corrections to the Kohn-Sham transitions yields the elusive double excitations that are missed by time-dependent DFT with the standard adiabatic…

Chemical Physics · Physics 2020-07-30 Francisca Sagredo , Kieron Burke

Knowledge of exact properties of the exchange-correlation (xc) functional is important for improving the approximations made within density functional theory. Features such as steps in the exact xc potential are known to be necessary for…

Strongly Correlated Electrons · Physics 2021-01-15 M. J. P. Hodgson , J. D. Ramsden , R. W. Godby

Recent progress in the field of (time-independent) ensemble density-functional theory (DFT) for excited states are reviewed. Both Gross-Oliveira-Kohn (GOK) and $N$-centered ensemble formalisms, which are mathematically very similar and…

Chemical Physics · Physics 2021-11-29 Filip Cernatic , Bruno Senjean , Vincent Robert , Emmanuel Fromager

By inverting the time-dependent Kohn-Sham equation for a numerically exact dynamics of the helium atom, we show that the dynamical step and peak features of the exact correlation potential found previously in one-dimensional models persist…

Chemical Physics · Physics 2022-07-28 Davood Dar , Lionel Lacombe , Johannes Feist , Neepa Maitra

We introduce a new functional for simulating ground-state and time-dependent electronic systems within density-functional theory. The functional combines an expression for the exact Kohn-Sham (KS) potential in the limit of complete electron…

Mesoscale and Nanoscale Physics · Physics 2021-01-15 M. J. P. Hodgson , J. D. Ramsden , T. R. Durrant , R. W. Godby

Conditional-probability density functional theory (CP-DFT) is a formally exact method for finding correlation energies from Kohn-Sham DFT without evaluating an explicit energy functional. We present details on how to generate accurate…

Chemical Physics · Physics 2022-05-04 Dennis Perchak , Ryan J. McCarty , Kieron Burke

We report a local, weight-dependent correlation density-functional approximation that incorporates information about both ground and excited states in the context of density-functional theory for ensembles (eDFT). This density-functional…

Chemical Physics · Physics 2020-06-05 Pierre-François Loos , Emmanuel Fromager

The Exact-Exchange (EXX) Kohn-Sham formalism, which treats exchange interactions exactly within density-functional theory, is applied to one-dimensional periodic systems. The underlying implementation does not rely on specific symmetries of…

Materials Science · Physics 2009-11-11 Stefan Rohra , Eberhard Engel , Andreas Goerling

Electronic structures are fully determined by the exchange-correlation (XC) potential. In this work, we develop a new method to construct reliable XC potentials by properly mixing the exact exchange and the local density approximation…

Chemical Physics · Physics 2024-08-06 Chen Huang

The question of how density functional theory (DFT) compares with Hartree-Fock (HF) for the computation of momentum-space properties is addressed in relation to systems for which (near) exact Kohn-Sham (KS) and HF one-electron matrices are…

Atomic Physics · Physics 2007-05-23 Sebastien Ragot

A recently developed quasi two-dimensional exact-exchange formalism within the framework of Density Functional Theory has been applied to a strongly inhomogeneous interacting electron gas, and the results were compared with state-of-the-art…

Condensed Matter · Physics 2009-11-07 S. Rigamonti , F. A. Reboredo , C. R. Proetto

A method is presented, which employs the density matrix renormalization group technique in order to construct exact ground state exchange correlation functionals for models of correlated electron systems coupled to external reservoirs. The…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Peter Schmitteckert , Ferdinand Evers

Quantum-electrodynamical density-functional theory (QEDFT) provides a promising avenue for exploring complex light-matter interactions in optical cavities for real materials. Similar to conventional density-functional theory, the Kohn-Sham…

Computational Physics · Physics 2024-02-16 I-Te Lu , Michael Ruggenthaler , Nicolas Tancogne-Dejean , Simone Latini , Markus Penz , Angel Rubio