Electronic structure and rebonding in the onionlike As@Ni₁₂@As₂₀ cluster

We present the ab initiostudy 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 [M. J. Moses, J. C. Fettinger, and B. W. Eichhorn, 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.