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

摘要

Small clusters of cobalt atoms, Co-n (n less than or equal to 3), were studied with the aid of the program deMon-KS module release 3.2, which is a density functional theory based method. Self-consistent-field model core potential (MCP) calculations, which describe the core electrons of the cobalt atom, were done in concert with the generalized gradient approximation (GGA) and local spin density approximation for the treatment of the exchange-correlation (XC) effects, MCP and all-electron (AE) calculations, at the same level of theory for XC, are compared and discussed. The obtained GCA-MCP results show a dramatical improvement in the calculated binding energies (BE), which is due to the accurate description of the XC energy, through CGA, and to a substantial reduction of the basis set superposition errors (BSSE). Finally, the present calculations are compared with other theoretical and experimental results obtained for these systems. (C) 2001 John Wiley & Sons, Inc. [References: 29]