CO ADSORPTION ON THE (001)-SURFACE OF MGO - A COMPARISON OF HARTREE-FOCK AND LOCAL-DENSITY FUNCTIONAL RESULTS

Hartree-Fock (HF) and local density functional (LDF) methods are applied to the study of the adsorption of CO to the (001) surface of MgO. The dependence of the chemisorption properties on the cluster size is studied; to this end adsorption at finite clusters and periodic slabs was considered. Both methods indicate a largely electrostatic MgO-CO bond. The HF results, however, show a more rapid convergence with cluster size than the LDF ones. This is connected to the more covalent description of the MgO electronic structure and of the MgO-CO bond in LDF compared to HF.