Phonon dynamics of plutonium chalcogenides and pnictides

We have investigated the phonon dynamics of the plutonium compounds (PuX; X = S, Se, Te, As, and Sb) by using rigid ion (RIM) and breathing shell models (BSM), later includes breathing motion of the electrons of the Pu-atoms due to f–d hybridization. We discuss the significance of these two approaches in predicting the phonon dispersion curves of PuX compounds and examine the role of electron–phonon interactions. Dominant ionic nature of bonding has been predicted for PuX compounds from the large LO–TO phonon splitting at zone center. We also report the one phonon density of states and first time calculated the lattice specific heat for these compounds.