Three-Body Nonadditive Free Energy of Gases Adsorbed on Solids of Arbitrary Electron Delocalization

Abstract

A general formalism is presented for the nonretarded interaction between three nonoverlapping systems of arbitrary sizes and electron delocalizations. The theory is formulated in terms of response functions and spatially dependent susceptibilities of the noninteracting systems. The three-body nonadditive free energy is worked out in detail and specialized to the interaction between two small nonpolar gas molecules adsorbed on the surface of a solid of arbitrary electron delocalization. Two extreme cases are considered:(1) the electrons in the solid are localized in small polarizable units and (2) the electrons in the solid are completely delocalized. The results are discussed and compared with previously derived expressions.