Density functional study of manganese dimer

Chemical bonding and magnetic interaction of manganese dimer (Mn-2) are still in controversy in experimental and theoretical studies. In this work, we examined various exchange correlation functionals of Kohn-Sham density functional theory (DFT), together with hybrid-DFT, and Hartree-Fock plus DFT approaches on description of Mn,. We found that, in contrast to pure DFT functionals, the experimentally reported features of chemical bonding and antiferromagnetic interactions of Mn, can be reproduced by employing the Hartree-Fock exchange terms. Thus, it is recommended to employ HF plus DFT, or hybrid DFT with large HF portion approach for the case that the direct interactions among manganese atoms play a major role to determine the electronic structure, such as manganese clusters. (C) 2007 Wiley Periodicals, Inc.