Crystal and electronic structure of BaB6 in comparison with CaB6 and molecular [B6H6](2-)

Barium hexaboride BaB6 has been obtained in the form of single crystals. It s crystal structure was refined in space group Pm (3) over barm (no. 271, a = 426.15 (7) pm). The electronic situation of BaB6 is discussed on the bas is of different band structure calculations performed within the density fu nctional theory (LMTO, plane wave). The comparison with CaB6 and the molecu lar anion [B6H6](2-) shows a similar band ordering. The different orbital c ontributions are strongly mixed and the inter-octahedral bonds are lower in energy than some of the intra-octahedral framework interactions. (C) 2001 Editions scientifiques et medicales Elsevier SAS. All rights reserved.