Phonon spectra and isothermal elastic constants forf-shell metals: A dynamical treatment

The two-body interaction is written as the sum of s-s,d-d overlap, d-d attractive, f-f overlap, and f-f attractive contributions. The free-electron part of the pair potential is obtained in second-order perturbation theory using a rational dielectric function and Heine-Abarenkov model pseudopotential. The overlap between d and f states of different ions and the effect of s-d and s-f hybridization are included in an approximate manner, as has been suggested by Wills and Harrison and by Harrison. The temperature dependence has been included through an asymptotic factor. The effective pair potential so defined is fast converging. It is then used to calculate the phonon spectra of rare-earth and actinide elemental metals in the fcc phase. The agreement between predicted and observed values is found to be reasonably good for all the metals. The binding energy and elastic constants of these metals are also calculated.