An orbital-dependent correlation energy functional in density-functional theory for the study of strongly-correlated electronic systems

Hiroshi Yasuhara, Masahiko Higuchi, Soh Ishii, Kenta Hongo, Yoshiyuki Kawazoe

Research output: Contribution to journalArticlepeer-review

Abstract

An orbital-dependent correlation energy functional Ec to be accompanied by the exact exchange energy functional Ex is proposed for applications of density-functional theory (DFT). The present Ec comprises spin-antiparallel and spin-parallel contributions, Ec σ-σ and Ecσσ. E cσ-σ is a modification of the spin-antiparallel component of the Hartree energy functional with a factor of ḡcσ-σ(r, r′) - 1 and E cσσ a modification of the spin-parallel component of the same energy functional with ḡc σσ(r, r′) where ḡc σσ(r, r′) (or ḡc σ-σ(r, r′)) is the spin-antiparallel(or the correlational part of the spin-parallel) coupling-constant-averaged pair correlation function. The present orbital-dependent ḡ σ-σ(r, r′) and ḡc σσ(r, r′) fulfill the symmetric property, the Pauli principle and the sum rules. In the limit of uniform density the two correlation functions are reduced to the very accurate analogues of the electron liquid that involve long-, intermediate-, and short-range correlations as well as their exchange counterparts. It is stressed that the correlation energy functional Ec in DFT should by its very nature be defined as a functional only of occupied Kohn-Sham orbitals and occupied Kohn-Sham energies for the purpose of employing the optimized potential method (OPM) to evaluate the correlation potential vc(r). The present scheme for E c, if applied to finite systems after making a suitable change in the treatment of long-range correlation, can give the correct asymptotic form of vc(r) of order r-4 for large r as well as the van der Waals potential.

Original languageEnglish
Pages (from-to)1402-1410
Number of pages9
JournalMaterials Transactions
Volume45
Issue number5
DOIs
Publication statusPublished - 2004 May

Keywords

  • Correlation energy functional
  • Density-functional theory
  • Electron liquid
  • Optimized potential method

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'An orbital-dependent correlation energy functional in density-functional theory for the study of strongly-correlated electronic systems'. Together they form a unique fingerprint.

Cite this