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Related papers: Almost Exact Exchange At Almost No Cost

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Most approximate exchange-correlation functionals used within density functional theory are constructed as the sum of two distinct contributions for exchange and correlation. Separating the exchange component from the entire functional is…

Condensed Matter · Physics 2009-10-28 Claudia Filippi , C. J. Umrigar , Xavier Gonze

Quantum rings can be characterized by a specific radius and ring width. For this rich class of physical systems, an accurate approximation for the exchange-hole potential and thus for the exchange energy is derived from first principles.…

Strongly Correlated Electrons · Physics 2009-02-04 E. Rasanen , S. Pittalis , C. R. Proetto , E. K. U. Gross

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 simple exact-exchange density-functional method for a quasi-two-dimensional electron gas with variable density is presented. An analytical expression for the exact-exchange potential with only one occupied subband is provided, without…

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

Semi-local density functionals for the exchange-correlation energy of electrons are extensively used as it produce realistic and accurate results for finite and extended systems. The choice of techniques play crucial role in constructing…

Materials Science · Physics 2017-11-01 Subrata Jana , Prasanjit Samal

We construct a nonlocal density functional approximation with full exact exchange, while preserving the constraint-satisfaction approach and justified error cancellations of simpler semilocal functionals. This is achieved by interpolating…

Chemical Physics · Physics 2009-11-13 John P. Perdew , Viktor N. Staroverov , Jianmin Tao , Gustavo E. Scuseria

Density-functional theory simplifies many-electron calculations by approximating the exchange and correlation interactions with a one-electron operator that is a functional of the density. Hybrid functionals incorporate some amount of exact…

Materials Science · Physics 2021-02-03 John Vinson

The exact-exchange (EXX) potential, which is obtained by solving the optimized-effective potential (OEP) equation, is compared to various approximate semilocal exchange potentials for a set of selected solids (C, Si, BN, MgO, Cu$_{2}$O, and…

Strongly Correlated Electrons · Physics 2016-08-07 Fabien Tran , Markus Betzinger , Peter Blaha , Stefan Blügel

The design of better exchange-correlation functionals for Density Functional Theory (DFT) is a central challenge of modern electronic structure theory. However, current developments are limited by the mathematical form of the functional,…

Chemical Physics · Physics 2024-08-19 Kyle Bystrom , Boris Kozinsky

Standard density functional approximations greatly over-estimate the static polarizability of longchain polymers, but Hartree-Fock or exact exchange calculations do not. Simple self-interaction corrected (SIC) approximations can be even…

Atomic and Molecular Clusters · Physics 2007-08-22 C. D. Pemmaraju , S. Sanvito , K. Burke

Implicit and explicit density functionals for the exchange energy in finite two-dimensional systems are developed following the approach of Becke and Roussel [Phys. Rev. A 39, 3761 (1989)]. Excellent agreement for the exchange-hole…

Strongly Correlated Electrons · Physics 2008-05-08 S. Pittalis , E. Rasanen , N. Helbig , E. K. U. Gross

Exact-exchange energy density and energy density of a semilocal density functional approximation are two key ingredients for modeling the static correlation, a strongly nonlocal functional of the density, through a local hybrid functional.…

Materials Science · Physics 2009-11-13 Jianmin Tao , Viktor N. Staroverov , Gustavo E. Scuseria , John P. Perdew

The flexibility of common generalized gradient approximation for the exchange-correlation energy is investigated by monitoring the equilibrium volume of transition metals. It is shown that no universal gradient-level approximation yielding…

Materials Science · Physics 2015-06-05 H. Levämäki , L. Vitos , M. P. J. Punkkinen , K. Kokko

For exchange-correlation functionals that depend explicitly on the Kohn-Sham orbitals, the potential $V_{\mathrm{xc}\sigma}(\re)$ must be obtained as the solution of the optimized effective potential (OEP) integral equation. This is very…

Materials Science · Physics 2009-11-07 Stephan Kümmel , John P. Perdew

The Gutzwiller approximate solution to the Gutzwiller wavefunction yields exact results for the Gutzwiller wavefunction in the infinite dimensional limit. Implicit in the Gutzwiller approximation is an approximate local form of the fermion…

Strongly Correlated Electrons · Physics 2009-07-27 Balazs Hetenyi , Hans Gerd Evertz , Wolfgang von der Linden

Most density functionals have been developed by imposing the known exact constraints on the exchange-correlation energy, or by a fit to a set of properties of selected systems, or by both. However, accurate modeling of the conventional…

Materials Science · Physics 2016-08-24 Jianmin Tao , Yuxiang Mo

The exact exchange potential in time-dependent density-functional theory is defined as an orbital functional through the time-dependent optimized effective potential (TDOEP) method. We numerically solve the TDOEP integral equation for the…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 H. O. Wijewardane , C. A. Ullrich

A new, very fast, implementation of the exact (Fock) exchange operator for electronic structure calculations within the plane-wave pseudopotential method is described in detail for both molecular and periodic systems, and carefully…

Materials Science · Physics 2018-12-12 Ivan Carnimeo , Stefano Baroni , Paolo Giannozzi

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

We show that the exchange statistics have consequences in 1D systems with compact topology, contrary to the common opinion that exchange statistics is arbitrary in 1D. As examples of non-trivial statistical behavior we exactly calculate the…

High Energy Physics - Theory · Physics 2008-02-03 Ilinski , G. V. Kalinin , V. S. Kapitonov
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