Model potential density functional study of small cobalt clusters, Co-n, n<= 3

Small clusters of cobalt atoms, Co-n (n less than or equal to 3), were stud ied with the aid of the program deMon-KS module release 3.2, which is a den sity functional theory based method. Self-consistent-field model core poten tial (MCP) calculations, which describe the core electrons of the cobalt at om, were done in concert with the generalized gradient approximation (GGA) and local spin density approximation for the treatment of the exchange-corr elation (XC) effects, MCP and all-electron (AE) calculations, at the same l evel of theory for XC, are compared and discussed. The obtained GCA-MCP res ults show a dramatical improvement in the calculated binding energies (BE), which is due to the accurate description of the XC energy, through CGA, an d to a substantial reduction of the basis set superposition errors (BSSE). Finally, the present calculations are compared with other theoretical and e xperimental results obtained for these systems. (C) 2001 John Wiley & Sons, Inc.