Valence transitions in rare-earth chalcogenides

Abstract
The equation of state for samarium chalcogenides is calculated at T=0 in a model in which the promotion of an electron from f level to d band is accompanied by a lattice contraction so that the chemical potential of the d electrons is reduced. With the nonlinearity in the lattice contraction as a function of d band occupation taken as a variable parameter and using known spectroscopic and elastic data on samarium chalcogenides, an equation of state is calculated which agrees to within 20% with the experimental results.