THEORY FOR THE POLARIZATION INTERACTION BETWEEN AN EXCESS ELECTRON AND A CLUSTER OF POLAR-MOLECULES

The polarization interaction between an excess electron and a cluster of polar molecules is discussed in a microscopic model and related to the dielectric continuum model. We obtain that the polarization of the bound electrons strongly reduces the strength of the interaction between the excess electron and the molecules by an effective screening. Previous calculations of the electronaffinity of clusters of polar molecules have used pair-potential interactions, which neglect these screening terms. Thus the attractive polarization energy has been overestimated, resulting in much larger vertical detachment energies than observed in the experiment.