Phonon spectra and isothermal elastic constants of transition metals: A dynamical treatment.

Abstract

The two-body interaction is written as the sum of s-s, d-d, and s-d contributions. The free-electron part of the pair potential is obtained in second-order perturbation theory using a rational dielectric function and an empty-core pseudopotential. The overlap between d states on different ions and the effect of s-d hybridization are included in an approximate manner, as has been suggested by Wills and Harrison. An approximate temperature dependence has been included in the effective potential through an asymptotic factor. The effective pair potential so defined is fast converging. It is then used to calculate the phonon spectra of Cu, Ag, Au, Ni, Pd, Pt, and Fe in real space. The agreement between predicted and observed values is found to be reasonably good for all these metals. The binding energy and elastic constants of these metals are also calculated.