van der Waals forces in the noble metals

Abstract

The van der Waals (or polarization) force between ions in the noble metals is calculated within a simplified model in which the ions are regarded as nonoverlapping and immersed in a uniform electron gas. The conduction-electron screening of the ion-ion interactions is straightforwardly taken into account. Using effective ionic polarizabilities derived from the measured optical constants, we find that the contribution of the polarization forces to the cohesive energy per atom is 0.21, 0.42, and 0.63 eV for Cu, Ag, and Au, respectively. By comparison, the total cohesive energies in these metals are 3.50, 2.96, and 3.78 eV, respectively.