THE DIPOLAR FRENKEL EXCITONIC INSULATOR PHASE OF AN IMPURITY IN A LIQUID SOLVENT - RESULTS

In a previous paper we have developed a mean field theory for the dipo lar Frenkel excitonic insulator (EI) phase of an impurity at infinite dilution in a liquid solvent or disordered matrix, a situation of expe rimental relevance. Based on this, we here present numerical results f or the location of the EI tranSition, and the impurity dipole moment i n the dipolar EI phase, using linear classical liquid state theories. For a non-polar polarizable solvent, we consider impurity and solvent atoms of (i) identical hard-sphere diameter, and (ii) differing hard-s phere diameter. We also generalize the previously studied model to all ow for dipolar polarizable solvent molecules, and present example resu lts. We consider in particular the case of alkali metal atoms dissolve d in methylamine, and conclude that a dipolar EI phase is possible for Li and Cs.