A self-consistent optical potential theory for atoms in solids

We develop an approximation for the optical potential in a solid, valid at intermediate energies, i.e. energies greater than 50 eV. The present approximation for the optical potential builds on the GW-expression. We separate the RPA polarization propagator into a core electron and a valence electron, and can then achieve a corresponding separation of the optical potential. We apply this method to electron-Ne and -Ar elastic scatterings and find a satisfactory agreement with the observed results. We also study the importance of self-consistency and the sensitivity to a parameter, the average excitation energy.