Universal correction for the Becke-Johnson exchange potential
Research output: Contribution to journal › Article › Scientific › peer-review
|Number of pages||5|
|Journal||Journal of Chemical Physics|
|Publication status||Published - 28 Jan 2010|
|Publication type||A1 Journal article-refereed|
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.
- density functional theory, electronic structure, exchange interactions (electron), DENSITY-FUNCTIONAL THEORY, COORDINATE-SPACE MODEL, STRONG MAGNETIC-FIELDS, SYSTEMS, OCTOPUS, TOOL