ELECTRONIC-STRUCTURE OF CUBIC URANIUM-COMPOUNDS

Self-consistent cellular multiple scattering techniques and photoemission energy distribution curves obtained at 20<hv<80 eV are used to study the density of states of UN and US. The calculations are based on a model using a finite cluster of atoms in a condensed-matter-like boundary potential. The main results refer to the mixing of the s, p, d, and f-states of uranium into a valence and a conduction band. The f-states form orbitals with the ligands, within the valence and conduction bands. In the nitride the amount of f character in the valence band is only 0.3 electrons and the f electrons are in two resonant levels (of each spin) in the conduction band. Only the first of these levels is occupied for the local, alternate from atom to atom, majority spin. In the sulfide the amount of f character in the valence band is 0.59 electrons and the rest of the f-levels are in a resonance state (of majority spin) at the beginning of the conduction band. The conduction band is mainly of localized uranium 6 d character. The theoretical results compare favorably with the photoemission data reported here. © 1979 Springer-Verlag.