Geometry, electronic structure and magnetism of small Co-n (n=2-8) clusters

The electronic structure, geometries and magnetic moment of small Co-n (n = 2-8) clusters have been studied by using nonlocal density functional calculations. The clusters are found to have abundant low-lying states corresponding to different geometries and spin multiplicities close to their ground states. The calculated bond dissociation energies in most cases are in good agreement with the collision-induced dissociation experiment. An equation is proposed to relate the calculated binding energies to the surface reaction rates between Co-n and D-2. The origin of the large magnetic moment has been successfully explained, Among the clusters Co-6 exhibits extra stability. No magnetic magic number has been found. (C) 1997 Elsevier Science B.V.