Some aspects of the electronic structure of uranium pnictides and chalcogenides

A simple model for the bonding between uranium f and pnictogen or chalcogen p electrons is described and estimates of the atom and angular momentum resolved contributions to the equation of state obtained. The results of full band calculations for the uranium chalcogenides and pnictides are summarized and the equation of state for UN analysed. The trends of the lattice parameter across the two series is reproduced theoretically by semirelativistic self-consistent calculations. Results of fully relativistic and semi-relativistic calculations compare favourably with photoemission results showing that in the pnictides the anion p-valence band lies at least 1 eV closer to the Fermi level than in the corresponding chalcogenide. (orig.)