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.