SIZE EFFECTS ON ADSORPTION ENERGIES OF COMPLEX ATOMS AND DIATOMIC-MOLECULES ON METAL-SURFACES FROM SMALL-CLUSTER CALCULATIONS

We present a new method for calculating binding energies of atoms and diatomic molecules chemisorbed on transition metal surfaces from cluster models. Our method relies on the separation between electronic and ionic contributions, by partitioning the desorption process into three steps. This allows us to remove the size effects due to the electronic relaxation by introducing the work function of the bare metal instead of the ionization potential of the cluster.