Electronic structure and f hybridisation of UX3 compounds

A wide range of behaviour is observed in uranium materials with stoichiometry UX,.Many compounds of this type are described well by density functional theory, but several are not. The results of fully relativistic self-consistent density functional calculations using the LMTO method are presented for the materials U S , , USn, and URu,. In the light of these results we discuss the applicability of band theory to these materials and indicate how this correlates with the position of the non-uranium atom in the Periodic Table. The importance of the f band width and the details of the hybridisation between uranium f states and non-f states on neighbouring sites are emphasised.