In Fig. (b)), the probability distribution of the counterion positions, as computed along the 36 ps MD trajectory of CV in toluene, is displayed. We find that in toluene, the counterion is preferentially located equidistant between the two nearest nitrogens, a configuration that is associated with a comparatively lower S 1 -S 2 splitting than the fully symmetry-broken configuration where the Cl -ion is mainly associated with a single N . This is in contrast to the behavior of CV in vacuum (see Fig. ), where the difference in the distance to the two nearest N atoms is significantly larger. Fig. shows not only a clear relationship between the distance difference and the S 1 -S 2 energy splitting, but also the relative position of the ion with respect to the nearest atom N and the energy difference. The average dimensionless difference in distance is 0.44, the average mean distance is 5.13 Å, and the dimensionless difference in energy is 0.18 along the vacuum trajectory, compared to the same quantities of 0.14, 5.24 Å, and 0.16 along the toluene trajectory. This suggests different counterion positions are sampled along these trajectories, with a greater S 1 -S 2 splitting along the vacuum trajectory. Consequently, we can conclude the solvent environment restrains the motion of the counterion, explaining the origin of the larger S 1 -S 2 split-ting observed in vacuum as compared to CV in toluene.