Additional sources of error could also contribute to the underestimation of the experimental spectral width of CV + in methanol. From our benchmark Franck-Condon calculations in implicit solvent, we know that the LC-ωHPBE functional produces a broader vibronic spectrum than CAM-B3LYP, and it may be that the larger de-gree of exact exchange is necessary to correctly model the ground and excited state curvature of CV + in methanol. An alternative possible source of error is that a higher lying state is contributing to the experimental absorption spectrum. One of the authors recently explored this nonadiabatic excited state mixing effect for the absorption spectrum of the methylene blue chromophore, finding significant spectral broadening due to nonadiabatic effects from S 1 and S 2 mixing. Although our QM/MM AIMD trajectories show minimal excited state mixing, without excited state calculations at a higher level of theory beyond TDDFT, it is difficult to know the correct excited state behavior for CV + , and some experimental results suggest nonadiabatic effects in the strongly coupled vibronic mode. Ultimately, higher accuracy will be achieved with the use of QM solvent during the dynamics, which potentially will allow for further coupling to either solvent dynamics or vibronic degrees of freedom.