A DFT + Umol model study of the self-interaction error in standard density functional calculations of Ni(CO) m (m = 1–4)

Abstract

The trend in the first ligand dissociation energies of the subcarbonyl and carbonyl complexes Ni(CO) m , m = 1–4, is a typical example for consequences of the self-interaction error in calculations using semi-local density functional approximations. The self-interaction effects on bond lengths and ligand dissociation energies are examined with the DFT + Umol approach, an extension of the DFT + U method to molecular orbitals. A detailed analysis shows that (1) the Ni 3d subshell is most affected by self-interaction and (2) the +Umol correction on the CO 2π* orbitals has no major positive effect on the nickel carbonyl complexes, at variance with similar models for the CO adsorption on surfaces of transition metals.