Dynamics of classical ionic plasmas in an electron gas

The Bohm-Staver treatment of electronic screening of long-wavelength ionic motions in a classical plasma is reexamined and extended to ionic mixtures. In the case of a pure ionic plasma the Bohm-Staver formula for the speed of sound is made consistent with the Ornstein-Zernike compressibility by the inclusion of two corrections arising from the thermodynamics of the bare plasma and from local pseudopotential effects. Consideration is also given to the effects of the electronic screening on the longitudinal excitation spectrum of a bare ionic mixture at long wavelengths, which contains an ionic plasma mode broadened by collisions as well as a relaxation mode of finite width.