Charge redistribution and polarization energy of organic molecular crystals - art. no. 195124

We present an approach to electronic polarization in molecular solids treat ed as a set of quantum systems interacting classically. Individual molecule s are dealt with rigorously as quantum-mechanical systems subject to classi cal external fields created by all other molecules and, possibly, external sources. Self-consistent equations are derived for induced dipoles and for atomic charges whose redistribution in external fields is given explicitly by an atom-atom polarizability tensor. Electronic polarization is studied i n two representative organic molecular crystals, anthracene and perylenetet racarboxylic acid dianhydride, and contrasted to previous results for syste ms of polarizable points. The stabilization energies of the neutral lattice , of isolated anions and cations, and of cation-anion pairs are found. Char ge redistribution on ions is included. The dielectric tensors of crystals a re successfully related to gas-phase properties and provide consistency che cks on polarization energies. The procedure is generally applicable to orga nic crystals in the limit of no intermolecular overlap.