Nonlocal approximation to the exchange potential and kinetic energy of an inhomogeneous electron gas

Abstract

A nonlocal approximation to the exchange energy and the exchange potential of an inhomogeneous electron gas is presented that is based on the conservation of the main characteristics of the correct Fermi hole. Tested for atoms, it gives better results than the local-density approximation. A new kinetic-energy functional in the Hartree-Fock approximation is also derived that depends explicitly on the exchange-correlation factor. When our nonlocal approximation is used in it, resonable results for the kinetic energy of atoms are obtained.