The structures and magnetic moments of Co-C clusters.

The geometries, binding energies, and magnetic moments of small CoC(N) (N = 1-8) and CO2C(N) (N = 1-6) clusters are studied systematically using all-electron density functional theory (DFT) with the generalized gradient approximation (GGA). The results indicate that, for the CoC(N) (N = 1-8) and Co2C(N) (N = 1-6) clusters, the lowest-energy structures are predicted to be linear structures except for CoC2 and CoC7. The ground states of the CoC(N) (N = 1-8) clusters are linear geometries (C(v)) with Co atom at one end. The ground states of the Co2C(N) (N = 1-6) clusters are linear geometries (D(h)) with the two Co atoms located at the two ends. For all the clusters, analysis of the Mülliken population shows that charge transfers from the Co atom(s) to the C atoms. The magnetic moment lies primarily on the Co atom(s).