Phonon Spectra of Some Transition Metal Carbides from a Simple Pseudopotential Approach

It is shown that many of the over-all features of the phonon spectra of transition metal carbides and related compounds can be approximately reproduced by a simple dielectric-response approach which uses Heine-Abarenkov pseudopotentials and free-electron screening, although the model calculations do not show the unusual structure seen in some of these materials. Illustrative applications are made to UC, HfC, TaC, and NbC.