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

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We study the accuracy of Kohn-Sham density functional theory (DFT) for warm- and hot-dense matter (WDM and HDM). Specifically, considering a wide range of systems, we perform accurate ab initio molecular dynamics simulations with…

Computational Physics · Physics 2024-11-21 Phanish Suryanarayana , Arpit Bhardwaj , Xin Jing , Shashikant Kumar , John E. Pask

We use Lanczos exact diagonalization to compute the exact exchange-correlation (xc) potential of a Hubbard chain with large binding energy ("the bulk") followed by a chain with zero binding energy ("the vacuum"). Several results of density…

Strongly Correlated Electrons · Physics 2015-06-11 Valentina Brosco , Zujian Ying , José Lorenzana

We compare two different approaches to investigations of many-electron systems. The first is the Hartree-Fock (HF) method and the second is the Density Functional Theory (DFT). Overview of the main features and peculiar properties of the HF…

Materials Science · Physics 2009-11-07 M. Ya. Amusia , A. Z. Msezane , V. R. Shaginyan

Kohn-Sham Density Functional Theory (KS-DFT) provides the exact ground state energy and electron density of a molecule, contingent on the as-yet-unknown universal exchange-correlation (XC) functional. Recent research has demonstrated that…

We study metallization of molecular hydrogen under pressure using exact exchange (EXX) Kohn-Sham density-functional theory in order to avoid well-known underestimates of band gaps associated with standard local-density or…

Materials Science · Physics 2007-05-23 Martin Staedele , Richard M. Martin

By exploiting freedoms in the definitions of 'correlation', 'exchange' and 'Hartree' physics in ensemble systems we better generalise the notion of 'exact exchange' (EXX) to systems with fractional occupations functions of the frontier…

Atomic Physics · Physics 2014-07-28 Tim Gould , John F. Dobson

We discuss energy densities in the strong-interaction limit of density functional theory, deriving an exact expression within the definition (gauge) of the electrostatic potential of the exchange-correlation hole. Exact results for small…

Chemical Physics · Physics 2012-11-14 André Mirtschink , Michael Seidl , Paola Gori-Giorgi

We incorporate in the Kohn-Sham self consistent equation a trained neural-network projection from the charge density distribution to the Hartree-exchange-correlation potential $n \rightarrow V_{\rm Hxc}$ for possible numerical approach to…

Computational Physics · Physics 2018-07-04 Ryo Nagai , Ryosuke Akashi , Shu Sasaki , Shinji Tsuneyuki

The inclusion of nucleonic exchange energy has been a long-standing challenge for the relativistic density functional theory (RDFT) in nuclear physics. We propose an orbital-dependent relativistic Kohn-Sham density functional theory to…

Nuclear Theory · Physics 2023-04-26 Qiang Zhao , Zhengxue Ren , Pengwei Zhao , Tae-Sun Park

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

We use the exact strong-interaction limit of the Hohenberg-Kohn energy density functional to construct an approximation for the exchange-correlation term of the Kohn-Sham approach. The resulting exchange-correlation potential is able to…

Strongly Correlated Electrons · Physics 2013-04-05 Francesc Malet , André Mirtschink , Jonas C. Cremon , Stephanie M. Reimann , Paola Gori-Giorgi

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

The derivative discontinuity in the exact exchange-correlation potential of ensemble Density Functional Theory (DFT) is investigated at the specific integer number that corresponds to the maximum number of bound electrons, $J_{max}$. A…

Quantum Physics · Physics 2011-11-09 Daniel L. Whitenack , Yu Zhang , Adam Wasserman

An exchange-correlation energy functional $ E_{\mathrm xc} $ and the resultant exchange-correlation potential $ v_{\mathrm xc}({\bf r}) $ in density-functional theory are proposed using orbital-dependent coupling-constant-averaged pair…

Strongly Correlated Electrons · Physics 2007-05-23 Hiroshi Yasuhara , Masahiko Higuchi , Yoshiyuki Kawazoe

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

Ensemble Density Functional Theory (EDFT) is a promising extension to Density Functional Theory (DFT) for calculating excited states. While Kohn-Sham eigenvalue differences underestimate gaps, EDFT has been shown to provide more accurate…

Materials Science · Physics 2026-02-10 Gregory G. V. Kenning , Remi J. Leano , David A. Strubbe

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

We derive an exact representation of the exchange-correlation energy within density functional theory (DFT) which spawns a class of approximations leading to correct long-range asymptotic behavior. In what amounts to be the simplest…

Materials Science · Physics 2009-11-10 Roi Baer , Daniel Neuhauser

An exchange energy functional is proposed and tested for obtaining a class of excited-state energies using density functional formalism. The functional is the excited-state counterpart of the local-density approximation functional for the…

Materials Science · Physics 2007-05-23 Prasanjit Samal , Manoj K. Harbola

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