Universal correction for the Becke-Johnson exchange potential
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Yksityiskohdat
Alkuperäiskieli | Englanti |
---|---|
Artikkeli | 044112 |
Sivumäärä | 5 |
Julkaisu | Journal of Chemical Physics |
Vuosikerta | 132 |
Numero | 4 |
DOI - pysyväislinkit | |
Tila | Julkaistu - 28 tammikuuta 2010 |
Julkaistu ulkoisesti | Kyllä |
OKM-julkaisutyyppi | A1 Alkuperäisartikkeli |
Tiivistelmä
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.