Nonlocal exchange- and kinetic-energy density functionals for electronic systems: Application to atoms and ions.

Abstract

The nonlocal weighted-density approximation (WDA) to the exchange- and kinetic-energy functionals of many-electron systems, proposed several years ago by Alonso and Girifalco within the framework of density-functional theory, is used to compute the ground-state electronic density and the total energy of atoms and ions with filled or half-filled electronic shells. The results and the results of analogous calculations using the well-known Thomas-Fermi-Dirac-Weizs\acker (TFDW) approximation for the kinetic (TFW) and exchange (D) energy density functionals are compared with Hartree-Fock values. A striking improvement of the total and exchange energies, of the density at the nucleus, and of the 〈${\mathit{r}}^{\mathrm{\ensuremath{-}}1}$〉 expectation values is obtained within the WDA scheme. The local behavior of the WDA electronic- and kinetic-energy densities is also analyzed.