Boron in ab initio calculations

Based on ab initio quantum chemical Hartee-Fock (HF) approximations, density functional theory (DFT) and LMTO-ASA methods, we have determined the geometric and electronic structures of atomic-scaled boron clusters, surfaces and nanotubes. The starting structures were constructed with the help of an 'Aufbau principle', previously proposed for boron clusters. In contrast to the semi-conducting alpha-boron, the boron sheets show a metallic behavior similar to graphite. Boron-based clusters could also serve as models to simulate silicon-based materials. (C) 1998 Elsevier Science B.V.