In turn, electronic excitation manifests in changes in the atomic partial charges and the -C=C-torsion potential as a minimum to finding appropriate MM models. While the actually relevant electronic excitation describing photoswitching refers to the adiabatic S1 state, a simple numerical trick in the DFT calculations is to first characterize the more stable T1 state, which corresponds to the lowest non-relativistic energy eigenstate for a total electron spin of 1, followed by subtracting two times the exchange potentials to yield the S1 energy. On this basis, numerically robust scans of torsional degrees of freedom and valence angles can be performed to parametrize the MM potentials. The underlying rigid scans require sterically reasonable starting points -which we picked from the DFT-relaxed S0-E and S1-syn (actually T1-syn) structures, respectively.