As a side note, we emphasize that the choice between this non-equilibrium vs equilibrium scenario may on the type of excitation and the physical process of interest. Polarity-sensitive dyes, for instance, exhibit strong Stokes shifts of the optical emission energy with respect to the absorption energy in strongly polar solvents such as water. Here, however, nuclear relaxation by far dominates the effects of electronic degrees of freedom. Baral et al. studied such nuclear relaxation effects for prodan also with coupled classical Molecular Dynamics-GW-BSE calculations (MM/GW-BSE), in which no electronic polarization from the embedding region was taken into account, but only electrostatic background from the reorienting solvent molecules. As shown in Figure , this allows us to capture the nuclear relaxation on ps timescale and calculated Stokes shifts in good agreement with the experiment. We will revisit such external coupling between GW-BSE and MM regions in the following section.