For all systems sampled, a fixed solvent response was coupled to each GBOM to obtain realistically broadened spectral lineshapes (see Appendix A 3). It is emphasized that the solvent parameters need not be varied to explore the statistical nature of the prefactor, as the solvent modes are assumed to follow Gaussian statistics and are thus described exactly by the second order cumulant approximation. Since in the cumulant approach, no distinction has to be made between whether fluc-tuations arise from solvent or chromophore degrees of freedom, a stronger or weaker coupling to solvent environment can be interpreted as adding or removing noninteracting Gaussian modes from the underlying "chromophore" GBOM. Therefore, the effect of stronger solvent coupling through the addition of more Gaussian fluctuations is directly incorporated in the GBOM sampling scheme.