Many-Electron Correlation Effects on the Metallic Interionic Potential

The self-consistent treatment of electron correlations in the electron liquid recently given by Singwi et al. is applied to calculations of the interatomic force constants in alkali metals. With the Ashcroft form of the pseudopotential, in which the only parameter is the core radius, reasonably good agreement with the force constants derived from neutron inelastic scattering data is obtained, confirming the results of a previous analysis of the phonon dispersion curves. The longitudinal sound velocities for the three main symmetry directions are calculated in the same scheme. Results for the effective interionic potential are presented and discussed.