Physisorption energies: influence of surface structure

Abstract

The crystal-face dependence of the physisorption energies for H 2 and D 2 interacting with low-index faces of Al and Cu has been measured. The effect is pronounced for Al. The data show that the (111) and (110) faces of Al display similar potential well depths, larger by 40% than the well depth for the intermediate (100) face. We discuss this surprising result in the light of conventional theoretical models and show, in particular, that these fail to take account of important non-asymptotic effects in the face-dependent electron density profiles.