Even with this activation step, we find that quite a few of the LR-TDDFT trajectories fail to proceed through MECP(C 2 C 3 ) on the timescale that we simulate. Many of them become trapped at S 1min (C 1 C 2 ), and a few others access the ground state via either MECP(NC 1 ) or MECP(C 4 C 5 ). In order to have a side-by-side comparison of similar dynamical pathways at different levels of theory, we discarded all but the trajectories that return to the ground state via MECP(C 2 C 3 ). This corresponds to 189 trajectories retained for the SF-BH&HLYP simulation, 112 retained for LR-ωB97X, and 85 for LR-ωB97X/TDA. All of the analysis below corresponds to these subsets of the 200 trajectories. Population decays from S 1 are plotted in Fig. (b) for this subset of trajectories, and then p(t) was fit to Eq. (20). Time constants and S 1 lifetimes are reported in Table .