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The derivative discontinuity of the exchange-correlation functional of density-functional theory is cast as the difference of two types of electron affinities. We show that standard Kohn-Sham calculations can be used to calculate both…

Chemical Physics · Physics 2007-12-13 F. P. Rosselli , A. B. F. da Silva , K. Capelle

We investigate an extension of excited state mean-field theory in which the energy expression is augmented with density functional components in an effort to include the effects of weak electron correlations. The approach remains…

Chemical Physics · Physics 2020-02-05 Luning Zhao , Eric Neuscamman

Ensemble density functional theory (eDFT) is an exact time-independent alternative to time-dependent DFT (TD-DFT) for the calculation of excitation energies. Despite its formal simplicity and advantages in contrast to TD-DFT (multiple…

Strongly Correlated Electrons · Physics 2017-01-19 Killian Deur , Laurent Mazouin , Emmanuel Fromager

Using an end-to-end differentiable implementation of the Kohn-Sham self-consistent field equations, we obtain an accurate neural network-based exchange and correlation (XC) functional of the electronic density. The functional is optimized…

Chemical Physics · Physics 2021-06-09 Sebastian Dick , Marivi Fernandez-Serra

We obtain the conductance of a system of electrons connected to leads, within time-dependent density-functional theory, using a direct relation between the conductance and the density response function. Corrections to the non-interacting…

Materials Science · Physics 2007-10-04 P. Bokes , J. Jung , R. W. Godby

A widely used approximation to the exchange-correlation functional in density functional theory is the local density approximation (LDA), typically derived from the properties of the homogeneous electron gas (HEG). We previously introduced…

Other Condensed Matter · Physics 2018-06-27 Mike Entwistle , Michele Casula , Rex Godby

We calculate the exact Kohn-Sham (KS) scalar and vector potentials that reproduce, within current-density functional theory, the steady-state density and current density corresponding to an electron quasiparticle added to the ground state…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 J. D. Ramsden , R. W. Godby

Density functional theory is the workhorse of modern electronic structure calculations, with wide-ranging applications in chemistry, physics, materials science, and machine learning. At its heart lies the exchange-correlation functional, a…

Chemical Physics · Physics 2026-02-20 Fabien Tran , Susi Lehtola , Stefano Pittalis , Miguel A. L. Marques

In the density functional (DF) theory of Kohn and Sham, the kinetic energy of the ground state of a system of noninteracting electrons in a general external field is calculated using a set of orbitals. Orbital free methods attempt to…

Strongly Correlated Electrons · Physics 2009-11-13 Jeng-Da Chai , John D Weeks

The ``extended Overhauser model'' [Overhauser, Can. J. Phys. 1995, 73, 683] for the calculation of the spherically and system-averaged pair density (APD) has been recently combined with the Kohn-Sham equations to yield realistic APD and…

Chemical Physics · Physics 2007-07-05 Paola Gori-Giorgi , Andreas Savin

The total energies and the spin states for atoms and their first ions with Z = 1-86 are calculated within the the local spin-density approximation (LSDA) and the generalized-gradient approximation (GGA) to the exchange-correlation (xc)…

Chemical Physics · Physics 2015-05-20 Eli Kraisler , Guy Makov , Itzhak Kelson

A decomposition of the exact exchange-correlation potential of time-dependent density functional theory into an interaction component and a kinetic component offers a new starting point for non- adiabatic approximations. The components are…

Chemical Physics · Physics 2018-11-14 Johanna I. Fuks , Lionel Lacombe , Soeren E. B. Nielsen , Neepa T. Maitra

The local density approximation (LDA) constructed through quantum Monte Carlo calculations of the homogeneous electron gas (HEG) is the most common approximation to the exchange-correlation functional in density functional theory. We…

Other Condensed Matter · Physics 2021-01-15 Mike Entwistle , Matthew Hodgson , Jack Wetherell , Bradley Longstaff , James Ramsden , Rex Godby

By introducing the self-energy density functionals for the dissipative interactions between the reduced system and its environment, we develop a time-dependent density-functional theory formalism based on an equation of motion for the…

Quantum Physics · Physics 2009-11-13 Xiao Zheng , Fan Wang , Chi Yung Yam , Yan Mo , GuanHua Chen

A curious behavior of electron correlation energy is explored. Namely, the correlation energy is the energy that tends to drive the system toward that of the uniform electron gas. As such, the energy assumes its maximum value when a…

Materials Science · Physics 2019-12-17 Teepanis Chachiyo , Hathaithip Chachiyo

In this work we give a comprehensive derivation of an exact and numerically feasible method to perform ab-initio calculations of quantum particles interacting with a quantized electromagnetic field. We present a hierachy of…

A functional $E_{xc}[\rho(\r,\epsilon)]$ is presented, in which the exchange and correlation energy of an electron gas depends on the local density of occupied states. A simple local parametrization scheme is proposed, entirely from first…

Materials Science · Physics 2009-11-10 Jose M. Soler

By studying the lowest excitations of an exactly solvable one-dimensional molecular model, we show that components of Kohn-Sham ensembles can be used to describe charge transfers. Furthermore, we compute the approximate excitation energies…

Chemical Physics · Physics 2018-05-22 Tim Gould , Leeor Kronik , Stefano Pittalis

This chapter presents the development of a density functional theory (DFT)-based method for accurate, reliable treatment of various resonances in atoms. Many of these are known to be notorious for their strong correlation, proximity to more…

Chemical Physics · Physics 2019-04-19 Amlan K. Roy

An approximate solution to the time-dependent density functional theory (TDDFT) response equations for finite systems is developed, yielding corrections to the single-pole approximation. These explain why allowed Kohn-Sham transition…

Materials Science · Physics 2009-11-07 H. Appel , E. K. U. Gross , K. Burke
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