Effect of Spatial Dispersion upon Physisorption Energies: He on Metals

Microscopic calculations of noble-gas adsorption on metals which include the effect of metallic nonlocal dielectric response are presented for two models of electronic boundary conditions at the metal surface. Spatial dispersion causes the Van der Waals interaction to decrease slower than the conventional d^-3 law indicates. Systematics of the physisorption indicate that interaction energies, but not equilibrium positions, are very sensitive to nonlocality. The results are relatively insensitive to to the details of the electronic boundary conditions.