On-top density functionals for the short-range dynamic correlation between electrons of opposite and parallel spin.

Autor: Hollett JW; Department of Chemistry, University of Winnipeg, Winnipeg, Manitoba, R3B 2G3, Canada., Pegoretti N; Department of Chemistry, University of Winnipeg, Winnipeg, Manitoba, R3B 2G3, Canada.
Jazyk: angličtina
Zdroj: The Journal of chemical physics [J Chem Phys] 2018 Apr 28; Vol. 148 (16), pp. 164111.
DOI: 10.1063/1.5025171
Abstrakt: Separate, one-parameter, on-top density functionals are derived for the short-range dynamic correlation between opposite and parallel-spin electrons, in which the electron-electron cusp is represented by an exponential function. The combination of both functionals is referred to as the Opposite-spin exponential-cusp and Fermi-hole correction (OF) functional. The two parameters of the OF functional are set by fitting the ionization energies and electron affinities, of the atoms He to Ar, predicted by ROHF in combination with the OF functional to the experimental values. For ionization energies, the overall performance of ROHF-OF is better than completely renormalized coupled-cluster [CR-CC(2,3)] and better than, or as good as, conventional density functional methods. For electron affinities, the overall performance of ROHF-OF is less impressive. However, for both ionization energies and electron affinities of third row atoms, the mean absolute error of ROHF-OF is only 3 kJ mol -1 .
Databáze: MEDLINE