Examination of several density functionals in numerical Kohn-Sham calculations for atoms

摘要

We studied several exchange-only and exchange-correlation energy density functionals in numerical, i.e., basis-set-free, nonrelativistic Kohn-Sham calculations for closed-shell IS states of atoms and atomic ions with N electrons, where 2 less than or equal to N less than or equal to 120. Accurate total energies are presented to serve as reference data for algebraic approaches, as do the numerical Hartree-Fock results, which are also provided. Gradient-corrected exchange-only functionals considerably improve the total energies obtained from the usual local density approximation, when compared to the Hartree-Fock results. Such an improvement due to gradient corrections is not seen in general for highest orbital energies, neither for exchange-only results (to be compared with Hartree-Fock results), nor for exchange-correlation results (to be compared with experimental ionization energies). (C) 2001 John Wiley & Sons, Inc. [References: 49]