VARIATIONAL WIGNER-KIRKWOOD H-EXPANSION

The variational content of the Wigner-Kirkwood h expansion of the dens ity matrix is analyzed in mean field approximation. A new variational method based on a strict expansion of the energy density in powers of h is established. It is applied to the case of Fermions moving in an e xternal potential, as well as to the self-consistent problem in semi-i nfinite matter. The standard density Functional theory is reviewed and contrasted with the new method. (C) 1998 Academic Press.