The initial population and subsequent depopulation of diabatic MLCT and 3 MC states mirror the ultrafast S N to T N intersystem crossing and T N to S 0 back-intersystem crossing established for the adiabatic electronic states in Figure (d). Interestingly, the population of the diabatic S 0 population is much smaller than the adiabatic S 0 population -compare Figures ) and (f). These states are defined in different manners, and thus, their populations may differ. The adiabatic S 0 state collects all states that are the lowest-energy singlet state at their respective geometry. In contrast, the diabatic S 0 states refers to the singlet state with the exact electronic character as the adiabatic S 0 at the Franck-Condon geometry, and the diabatic S 0 populations collects their components in the trajectories during the dynamics.