The spectra generated using the nuclear ensemble approach, as shown in Figure , reveal that the VDEs exhibit larger fluctuations than the VEEs, resulting in an emission spectrum that is significantly broader than the absorption spectrum. This is evidenced by the standard deviation of the energies and the FWHM of the emission spectrum being almost twice as large as those of the absorption spectrum, see Table . We also analyzed the impact of chromophore-only configurations on spectral broadening and found that chromophore motion is the main driving factor for VDE distribution. Please refer to SM, Section S6 and Figure for a detailed discussion.