Energies of atoms with nonspherical charge densities calculated with nonlocal density-functional theory

Calculations using nonlocal density-functional theory show that the total energies of atoms in states characterized by partially filled degenerate subshells are substantially lower when the charge density is not spherically averaged. This is in contrast to the case with local density theory in which spherical and nonspherical treatments of atoms give essentially identical energies. A cooperative effect of nonlocality in the exchange-correlation functional and nonsphericity in the charge density lowers the atomic total energies and greatly improves the calculated binding energies of ${\mathrm{B}}_2$, ${\mathrm{C}}_2$, ${\mathrm{O}}_2$, and ${\mathrm{F}}_2$.