Solvent structure in particle interactions. Part 1.—The asymptotic regime

The structural contribution to dispersion energies is obtained for the interaction of two solute molecules immersed in a liquid, for a solvent molecule with a wall, and for two half-spaces separated by a liquid. The interaction potentials are derived from the Ornstein–Zernike equations using the known asymptotic forms of the direct correlation functions. While the expressions obtained derive from a specific molecular interaction model they have wider validity. Significant changes emerge in the usual Hamaker or Lifshitz expressions based on a continuum solvent picture even at distances of the order of 50 Å for systems with small Hamaker constants.