The RR experiments yield the frequencies of the vibrational modes {ω α } and also the Huang-Rhys factors S α which are extracted by fitting the signal to the RR cross section. The analysis also yields contributions due to solvent, and other (sub 200 cm -1 ) nuclear modes that cannot be experimentally resolved, to the overall line shape and Stokes shift which are captured by an overdamped oscillator with correlation time 1 Λ and reorganization energy λ 0 . The procedure that is rou-tinely done to extract these parameters is detailed in the supplementary information.