Analysis of the ’’charge resonance’’ transition in anthracene dimer anion

The experimentally observed ’’charge resonance’’ transition of anthracene dimer anion is explained in terms of the resonance interaction of the lowest unoccupied orbitals of neighboring anthracene molecules. The distortion energies of the anthracene molecule and anion are shown to make an important contribution to the excitation energy. The numerical estimate of the resonance integral, based on the experimental absorption energy of the dimer anion, is shown to be related to that which is appropriate for a calculation of electron mobility in crystalline anthracene.