Electronic structure and rebonding in the onion-like As@Ni12@As20 cluster

We present the first ab initio study of the geometry, electronic structure, charged states, bonding and vibrational modes of the recently synthesized fullerene-like As@Ni12@As20 cluster which has icosahedral point symmetry [Science, 300, 778 (2003)]. We show that the molecule is vibrationally stable and will be electronically most stable in its -3 oxidation state in the condensed phase and in -2 state in the gas phase. We examine the bonding in this unusually structured molecule from charge transfer between atoms, infrared and Raman spectra, and charge density isosurfaces.