Density functional theory investigation on the structure and stability of Sc2Bn (n=1-10) clusters

The geometries, stabilities, and electronic properties of Sc2Bn clusters, up to n = 10, have been systematically investigated by using the density-functional B3LYP and CCSD(T) method. It was found that the ground state structures of the B clusters are substantially modified by the doping of Sc atoms. Sc2Bn clusters have very regular growth pattern, namely to form bipyramid. All the most stable Sc2Bn can be viewed as bipyramid (uncompleted when n <= 5) with two Sc atoms at the apexes. Sc2B7 and Sc2B8 are confirmed as the magic number clusters based on the analysis of the second-order difference of energies. The dissociation energies, vertical ionization potentials (VIP) and electron affinities (VEA) of Sc2Bn isomers are discussed. In most of the case, the Sc2Bn clusters have smaller HOMO-LUMO gap, VIP, VEA than the corresponding B-n clusters. There was no explicit correlation between the energetic stability and HOMO-LUMO gap, VIP or VEA. (C) 2013 Elsevier B.V. All rights reserved.