Excited-State Vibrations of Solvated Molecules: Going Beyond the Linear-Response Polarizable Continuum Model

In this work we compare the excited-state vibrational patterns computed in gas and condensed phases, the latter being modeled with the Polarizable Continuum Model. For the first time we compare the results of two alternative theoretical approaches that is a standard linear-response approximation and a state-specific description, within the corrected linear-response formulation. Using five test molecules, we show that the point group symmetry of the excited-state geometry might differ with the linear and corrected linear-response models. The vibrational frequencies obtained with the latter model are often rather close to their gas counterparts, whereas the linear-response model tends to overestimate solvation effects. The differences in zero-point vibrational energies between the excited and ground states have also been evaluated, and the impact of the selected solvent model is generally limited for this average parameter.