In principle, QM/MM modeling also provides a reference for calibrating the Apparent Surface Charge models. Specifically, one can generate the average solvent environment configuration (ASEC) from explicit solvent QM/MM (if not full-QM) molecular dynamics simulations and then project all ASEC solvent charges onto the chromophore molecular surface, which can then be used to assess/improve the quality of screening charges in the Apparent Surface Charge models.