Exchange-correlation energies and correlation holes for some two- and four-electron atoms along a nonlinear adiabatic connection in density functional theory

The adiabatic connection procedure of density functional theory has been applied to two- and four-electron atomic systems by following a nonlinear path that leads from the noninteracting Kohn-Sham reference system to the physical one. We have calculated the exchange and correlation energies as the interaction strength is increased, as well as the densities of the corresponding correlation holes. (C) 2002 Wiley Periodicals, Inc.