A vibronic problem of solvated electrons

Abstract

An attempt is made to understand the relationship and the essential difference between the two alternative approaches to the absorption spectra of solvated electrons; the standard single-site models and the multiple-site (“electron-transfer”) formulation. Using two phenomenological models, it is shown that the spectral line widths predicted by the single-site models are necessarily narrower than those calculated by the electron transfer model, because of the restricted choice of the configuration coordinate in the former category. Such restriction arises from the assumption of the rigid medium potential for the excess electron and also from imposing the Born-Oppenheimer separability of electronic and nuclear wavefunction for the excited states which are extended over many solvent molecules, in the single-site models. The peak transition energies are nearly identical for the two approaches.