Kinetic-energy functional of the electron density

Abstract

A kinetic-energy functional of the electronic density is presented. This functional is based on an integral form and is correct through second order in the response. The formulas are compared numerically with the Thomas--Fermi--von Weizs\"acker--like formulas and favorable results are found. These formulas correctly give both shell structures in the electron densities of atoms and bond charges in the electron densities of solids. This quantum oscillation in the electron density is lacking in the densities of previous kinetic-energy functionals and is regarded as the major achievement of the current approach.