Resonance Raman Spectra Interpretation by Molecular Coherent State Representation

Abstract

Abstract. In this paper the problem of exact summation over vibrational states of intermediate electronic level excited by resonance Raman scattering in a molecular system with an arbitrary number of vibrational modes is solved with the help of the coherent state representation. For matrix elements of the resonance Raman (RR) amplitude the expressions in the form of an integral and multiple series as well as recurrence relations are obtained. The interpretation of RR spectra of linear-chain mixed-valence platinum complexes is given as an illustration. IntroductionResonance Raman (RR) band intensities in molecular systems are described, as a rule, by the second-order perturbation theory [1] that connects intensities with the polarizability tensor. The vast field of RR spectroscopy on crystals is usually described by the third-order perturbation theory [2] using a susceptibility tensor. Though historically the descriptions of RR experiments in molecules and solids have developed independently, the fundamental physical processes are identical. Hence, in [3], an attempt to apply the perturbation theory of the third order to molecular RR scattering was made. As shown in [4], the methods [1] and [3] are equivalent.