POLARIZATION ENERGY OF A LOCALIZED CHARGE IN A MOLECULAR-CRYSTAL

A method is developed which gives an explicit self-consistent algebraic expression for the polarization energy of a point charge localized in a perfect molecular crystal in terms of Fourier transformed lattice multipole sums. An exact macroscopic expression is derived for the long-range contribution. Calculations of the polarization energy in anthracene and naphthalene are presented for several molecular polarizabilities. The results confirm those obtained by the self-consistent polarization field method and agree with experiment, though the point-molecule approximation is not strictly adequate. The method may be extended to calculate the forces on molecules and the electron-phonon coupling due to polarization fluctuations. © 1979.