Tampere University of Technology

TUTCRIS Research Portal

Universal correction for the Becke-Johnson exchange potential

Research output: Contribution to journalArticleScientificpeer-review

Details

Original languageEnglish
Article number044112
Number of pages5
JournalJournal of Chemical Physics
Volume132
Issue number4
DOIs
Publication statusPublished - 28 Jan 2010
Externally publishedYes
Publication typeA1 Journal article-refereed

Abstract

The Becke-Johnson exchange potential [A. D. Becke and E. R. Johnson, J. Chem. Phys. 124, 221101 (2006)] has been successfully used in electronic structure calculations within density-functional theory. However, in its original form, the potential may dramatically fail in systems with non-Coulombic external potentials, or in the presence of external magnetic or electric fields. Here, we provide a system-independent correction to the Becke-Johnson approximation by (i) enforcing its gauge-invariance and (ii) making it exact for any single-electron system. The resulting approximation is then better designed to deal with current-carrying states and recovers the correct asymptotic behavior for systems with any number of electrons. Tests of the resulting corrected exchange potential show very good results for a hydrogen chain in an electric field and for a four-electron harmonium in a magnetic field.

Keywords

  • density functional theory, electronic structure, exchange interactions (electron), DENSITY-FUNCTIONAL THEORY, COORDINATE-SPACE MODEL, STRONG MAGNETIC-FIELDS, SYSTEMS, OCTOPUS, TOOL