Polarization energy of a localized charge in a molecular crystal. IV. Effect of polarizability changes

The Fourier transform method and submolecule treatment described previously are used to derive an exact expression for the change ΔP in polarization energy of a localized charge when some of the surrounding molecules have polarizabilities different from those in the perfect crystal. The crystal structure is assumed unchanged. The method can be applied to vacancies, charged exciton complexes and X traps. It is illustrated by calculations of ΔP for isolated unrelaxed vacancies in anthracene. If the charge is not too near the vacancy, - ΔP equals the charge-induced-dipole energy in an isotropic continuum having the average dielectric constant for anthracene.