The spectra generated from the high-frequency region of the spectral density (above 200 cm -1 , Figure ) reveals the underlying vibronic structure, with the QUBEKit and revQUBEKit spectra showing more structure due to the increased intensity of the peaks in the high-frequency region of the spectral density above 750 cm -1 . The spectra generated from the low-frequency region of the spectral density below 200 cm -1 , Figure , correspond to inhomogeneous broadening from the solvent dynamics and show a Gaussian form. Here we can see that the trend in the spectral width parallels both the intensity in the low-frequency region of the spectral density, Figure , and the low-frequency reorganization energy value, with the QUBEKit spectrum being the most narrow, followed by revQUBEKit and then QM/MM spectra. Overall, we can consider the total absorption spectrum as a combination of the low and high-frequency contributions, where we see that QM/MM gives more broadening from the low-frequency contribution due to stronger coupling to the solvent environment, but less broadening from the high-frequency contribution due to weaker vibronic coupling to the chromophore degrees of freedom.