A systematic method of treating multiplets in the density functional theory is presented. An optimized potential method is introduced for the lowest-lying multiplets. A method proposed recently by the author is used to generalize the Krieger, Li and Iafrate (KLI) approximation for multiplets. The generalized exchange-only KLI exchange potential leads to results as good as the Hartree-Fock results. Inclusion of the simple local Wigner correlation results in an improvement only in the total energies, whereas the multiplet splitting becomes even worse. The multiplet separation can be approximated by a very simple expression containing the average density and the difference of the Kohn-Sham potentials.
|Number of pages||11|
|Journal||Journal of Physics B: Atomic, Molecular and Optical Physics|
|Publication status||Published - Jun 28 1999|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics