Dynamical susceptibility and neutron scattering cross esection of a model mixed-valence system

The authors have calculated the q and w-dependent spin and charge response functions as a function of temperature for an Anderson lattice. Operators are defined for the f electrons which restrict the occupancy to fsup(n) and fsup(n+1). The one-particle Green's function results are similar to earlier approaches and the main effect of the on-site correlations on the two particle Green's function is to introduce kinematic restrictions on the f-site occupancies. These calculations account reasonably well for the behavior of the inelastic peak seen in neutron studies of Grier and Shapiro in TmSe. The charge response function is used to calculate the qualitative behavior of the phonon dispersion curves and results in interesting non-adiabatic behavior in the phonon spectrum. (Auth.)