Icosahedral B-12, macropolyhedral boranes, beta-rhombohedral boron and boron-rich solids

摘要

The preference for icosahedral B-12 amongst polyhedral boranes and elemental boron is explained based on an optimization of overlap model. The ingenious ways in which elemental boron and boron-rich solids achieve icosahedron-related structures are explained by a fragment approach. The Jemmis mno rules are used to get the electron requirements. The extra occupancies and vacancies in beta-rhombohedral structures are shown to be inevitable results of electron requirements. The detailed understanding of the structure suggests ways of doping beta-rhombohedral boron with metals for desired properties. Theoretical studies of model beta-rhombohedral solids with metal dopings provide support for the analysis. (c) 2005 Elsevier Inc. All rights reserved.