F-center induced Raman scattering in RbCl

Experimental Raman spectra of RbCl containing F-centers are reported. Lines of A_1u, E_u and F_2u symmetry were observed. Calculations of the first-order Raman spectra are presented; they have been based on the assumption that the electron-phonon interaction is linear with displacements of F-center nearest neighbours. A shell-model fitted to neutron data was used to evaluate the Green-function matrix elements and the projected densities of states. The best agreement between theory and experiment was found to occur when using a zero-force-constant change for the F_2u spectrum and a 0·35 fractional decrease in the longitudinal force-constant A₁₂ for the A_3u and E_u spectra.