SCREENING OF INTERMOLECULAR FORCES IN ADSORBATES

The interaction potential of a pair of adsorbed molecules differ from that of the same molecules in free space, because of the response of the substrate. This response does not influence much the short-range repulsive part of the potential; only the long-range attractive part is affected. The change due to the influence of the substrate has been the subject of extensive study, both theoretically and experimentally. In this paper the problem is formulated in terms of the dynamic charge response properties of the interacting pair, and applications to the case of adsorbed molecules on model metal surfaces is described.