ELECTRONIC BAND-STRUCTURE OF THNISN

One-electron energy band structure for ThNiSn, which is a proper reference material for the study of the anomalous physical properties of UNiSn, is calculated by a self-consistent APW method with the local density approximation. To clarify the feature of band structure, the band calculation is performed for the isostructural ThRhSb and the NaCl type ThSb, too. The valence bands consist of the Sn 5p and Ni 3d states. Due to the strong mixing of Sn 5p and Ni 3d states, the bonding and anti-bonding bands are formed and the non-bonding Ni 3d bands locate between them. The conduction bands are derived from the Th 6d states and are raised by the mixing of Th 6d and Ni 3d states. A band gap appears between the occupied valence bands and the empty conduction bands. The mechanism of anomalous properties of UNiSn is considered. © 1990.