Crystal and electronic structure of BaB6 in comparison with CaB6 and molecular [B6H6]2−

Abstract

Abstract Barium hexaboride BaB 6 has been obtained in the form of single crystals. Its crystal structure was refined in space group Pm 3 m (no. 221, a =426.15 (7) pm). The electronic situation of BaB 6 is discussed on the basis of different band structure calculations performed within the density functional theory (LMTO, plane wave). The comparison with CaB 6 and the molecular anion [B 6 H 6 ] 2− shows a similar band ordering. The different orbital contributions are strongly mixed and the inter-octahedral bonds are lower in energy than some of the intra-octahedral framework interactions.