Information on the Exciton Band Structure of the 1B2u State of Crystalline Naphthalene from the Variation of Energy Denominators Method

Abstract

Perturbation shifts of guest levels in isotopic mixed crystals of naphthalene have been determined. These data verify that the density function for exciton states is almost symmetric over the entire exciton band of the first singlet state. This result agrees with the entire band structure as observed in band-to-band transitions and disagrees with the band structure calculated from the octopole model for the inter-molecular interaction. The transition energies of guest levels also disagree with a model for the exciton splitting involving configuration interaction with charge transfer states. A possible source of the exciton splitting is suggested, and the available data for evaluating theoretical descriptions are outlined.