Iwami Higashi and Toshio Ishii
Department of Chemistry, Chiba Institute of Technology, Shibazono, Narashino, Chiba 275-0023, Japan
(Received September 25, 2001; Accepted October 5, 2001)
Keywords: Boron-Rich Solids, B12 Icosahedron, b-Rhomboheral Boron, a-AlB12, YB66
Abstract. Two-dimensional icosahedral B12 networks in boron-rich crystals have been examined on the basis of crystal structure data. The linkages between the icosahedral B12 units within the networks are effected approximately along the five-fold axis of B12 icosahedron. Features of the icosahedral B12 networks as well as the external appearances of individual icosahedral B12 units are discussed in connection with the crystal structure-type in which the B12 networks are present. The crystal phases used for the calculations of icosahedral B12 structures are as follows: a-rhombohedral boron, b-rhombohedral boron, a-tetragonal boron, a-AlB12, g-AlB12, AlMgB14, AlB24C4, YB66 and YB41Si1.2.