Quantification of contaminants to incoherent nuclear resonant scattering

We calculate the contribution of inelastic electronic x-ray scattering to inelastic incoherent nuclear resonant scattering measurements. We discuss the propagation of plane waves in a medium with a strong energy-dependent index of refraction and treat the inelastic electronic scattering in the kinematical approximation. In experimentally relevant situations, the electronic admixture proves negligible. We conclude that inelastic incoherent nuclear resonant scattering provides partial, vibrational densities of states for the resonant nuclei.