For SAM 3.5 Å, for the presented trajectory (see the right column of Figure ), the exciton is more delocalized (than for SAM 5.5 Å) while the system resides in the ππ * states. However, a partial localization is observed during dynamics in the ππ * manifold (compare to the initial IPR value of ∼3.8 for the given trajectory). The CT contributions are larger for SAM 3.5 Å, and become dominant at some times, e.g. CT reaches values of up to 0.9 between 35 and 100 fs. At 35 fs, we also observe an upward surface hop from the initially populated S 8 state to S 10 , which is accompanied by the change in CT from ∼0.2 to ∼0.9. We also observe an increase in CT up to ∼0.45 at around 1100 fs, which is again associated with upward nonadiabatic transitions (from S 5 in this case). Once the nπ * states are populated, the exciton becomes strongly localized (the IPR, F H and F 33 values are 1), on the third monomer in the presented case (X = 3). We also observe spikes in FTDM and IPR curves (while being in the nπ * manifold) correlated with surface hops between S 1 and S 2 .