Green's-function calculation of electron screening in a plasma

Extensions to the finite temperature Green's-function method fur the calcul ation of equilibrium densities within the Kohn-Sham formulation of density functional theory are presented. In particular, an expression fur the densi ty in terms of single-particle Green's-function differences summed over all Matsubara poles is utilized. Numerical methods for the evaluation of this infinite sum are given. This formulation automatically includes discrete as well as continuum states, is valid for finite temperatures, and is especia lly well suited for high temperatures. Techniques are also presented for th e calculation of single-pal-tide Green's functions fur spherically symmetri c systems and arbitrary complex energies. The usefulness of these methods i s demonstrated by their application to the problem of electron screening of nuclei in a plasma. Direct comparison is made with previous finite tempera ture, Kohn-Sham, wave function type calculations for protons and for neon n uclei in an electron gas. [S1063-651X(99)07203-7].