The surface hopping MD simulations were performed starting in the brightest nπ * adiabatic state, thus modeling nonadiabatic relaxation after excitation with visible light. The evolution of the ensemble-averaged PN in time is shown in Fig. . The left panel shows the whole simulation period of 10 ps, whereas the right panel zooms into the first 20 fs. As already described in the previous subsection, the initial excitons are strongly localized, with the PN values at t = 0 being less than 1.1. Remarkably, during the short-time dynamics (t < 10 fs) the excitons become even more localized as can be seen from the right panel of Fig. , with the PN values approaching ∼1.00. Using a simple exponential fit of the form