Resonance Raman spectra of bromine: Scattering cross‐sections for simultaneous resonance with two excited states, B3∏ (0+) and 1∏(1)

This paper is concerned with the quantitative interpretation of the resonance Raman excitation profile (REP) of bromine. This is the first example of a diatomic molecule where two excited electronic states, B3∏ and 1∏, strongly intervene in the Raman tensor. The numerical calculations of all the Franck–Condon factors and densities for both excited electronic states using RKR methods are presented. The results are then applied to the calculation of the REP. This rigorous calculation is compared with an approximate method, the reflection approximation. The main properties of the REP, in particular the presence of a strong maximum on the red wing of the absorption band, are accounted for by the present theory and the contributions of the two excited electronic states are discussed.