simple tests for density functional methods

Gábor I. Csonka, Nam Anh Nguyen, István Kolossvary

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22 Citations (Scopus)

Abstract

The performance of the currently used generalized gradient approximation density functionals is analyzed using several simple, yet critical requirements. We analyze the effects of the self-interaction error, the inclusion of the exact exchange, and the parameter settings used in the popular three-parameter hybrid density functionals. The results show that the elimination of the self-interaction error from the current density functionals lead to very poor results for H2. The inclusion of the exact exchange does not significantly influence the self-interaction corrected results. The variation of the A, B, and C parameters of a hybrid DFT method influences the H - H equilibrium bond length through a very simple linear equation, and it is possible to reproduce the experimental H - H distance with appropriate selection of these parameters, although an infinite number of solutions exists. Similar results were obtained for the total energy and the electron density along the internuclear axis. The analysis of the exact KS potential at the bond critical point of the dissociating H2 molecule shows that, for this property, the second order Moller-Plesset perturbation theory yields a better potential than the density functionals studied in this article.

Original languageEnglish
Pages (from-to)1534-1545
Number of pages12
JournalJournal of Computational Chemistry
Volume18
Issue number12
DOIs
Publication statusPublished - Sep 1997

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Keywords

  • Electron density
  • Equilibrium bond length
  • H, total energy
  • Hybrid functionals
  • KS potential
  • Self-interaction error

ASJC Scopus subject areas

  • Chemistry(all)
  • Computational Mathematics

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