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 functi onal calculations. The clusters are found to have abundant low-lying s tates corresponding to different geometries and spin multiplicities cl ose to their ground states. The calculated bond dissociation energies in most cases are in good agreement with the collision-induced dissoci ation experiment. An equation is proposed to relate the calculated bin ding energies to the surface reaction rates between Co-n and D-2. The origin of the large magnetic moment has been successfully explained, A mong the clusters Co-6 exhibits extra stability. No magnetic magic num ber has been found. (C) 1997 Elsevier Science B.V.