and implemented in a development version of the open-source package OpenMolcas. The current formulation of the energy, which has been in use in (Open)Molcas, relies on the state-averaged solute energy with a state-specific solvation model (Eq. ( )) for SA-MCSCF. For regions of state crossings, the solvent charges are polarized with respect to the averaged density of the crossing states, ensuring that the PESs near the crossing region remain smooth, as illustrated in Figures and. As discussed, an approximate electronic gradient is employed to solve the SCF equation. However, analytic derivatives can be obtained by using the exact gradient of the approximate electronic gradient and solving a modified Z-vector equation with internal state rotations. We observed that fully relaxing the solvent charge with the CASPT2 density had a negligible effect on the excitation energy, indicating that the PTE approach is sufficient for CASPT2 with PCM. The experimental solvatochromic shift could also be reproduced using this method and explicit solvent molecules.