Intermolecular interactions in the presence of an intense radiation field

Abstract

It is well known that the R ^-6 dependence of the dispersion interaction is modified to R ^-7 at large intermolecular separations where retardation effects play an important role. In this paper, the theory of intermolecular interactions between two non-polar molecules in the presence of an external radiation field is given and a general expression for the interaction energy is obtained. The form of the potential energy is examined when the molecular pair is oriented with respect to the incident radiation and the incident beam is either linearly or circularly polarized. The interaction energy after tumbling average shows R ^-1 dependence in the near zone and a modulated R ^-2 behaviour in the far zone.