Bonding and polyhedral atomic volumes for the transition metal borides

Abstract

The results of Pauling's metallic radii and PAV calculations provide an estimate of effective charges, valences, atomic volumes, and non-integral coordination numbers for a wide selection of rare earth and transition metal binary borides. This uniform treatment suggests that effective charges for the transition metals are generally less than one, and that their valence is lower than the usual Pauling maximum of six. In addition, it was noted that the boron PAV volume was related to the non-isonomicity of the cell and that the use of ƒ orbitals in the BOA technique provides a useful discussion of bonding in some of the rare earth diborides not readily treated by s, p, and d hybridization alone.