As expected the overall polarization effects are observed to be important when replacing QM waters with MM waters. However, the difference observed between the WAT and M2P2 water models is minor and for one-photon absorption properties not observed to be significant. The M2P2 model is computed for each water molecule individually and this adds both complexity and simulation time when performing simulations. As observed in earlier work, hybrid models combing WAT with M2P2 have been observed to provide an excellent compromise keeping M2P2 waters near the QM region with the rest either being treated with WAT or TIP3P. Nonetheless, such hybrid models are not investigated in this work.