NMD simulations for trans-PSB3 were performed using the augmented fewest-switches surface hopping (aFSSH) algorithm, a modification of the original fewest-switches algorithm to account for decoherence effects. Separate simulations were performed using LR-TDDFT (both with and without the TDA) and also SF-TDDFT. For the LR-TDDFT simulations we used the ωB97X functional, and for SF-TDDFT we used BH&HLYP. (Early benchmarks of SF-TDDFT demonstrated that a functional with 50% exact exchange works well, 7 a fact that was later justified theoretically, and BH&HLYP has become the de facto standard for use with SF-TDDFT. ) The 6-31G* basis set was used for all aFSSH simulations. All calculations were performed using a locally-modified copy of Q-Chem, v. 4. A set of 200 aFSSH trajectories were computed at each level of theory. The initial nuclear configurations and momenta were sampled according to the Wigner distribution for the quantum harmonic oscillator, with harmonic frequencies and normal modes obtained from ground-state MP2 calculations. At t = 0 in the simulations, the S 1 state is populated at the ground-state geometry and each trajectory was then propagated in time for 9,000 a.u. (≈ 218 fs), using a time step of 20 a.u. (≈ 0.484 fs). These trajectories are intended to model a real photoexcitation of PSB3. For reasons described below, we also propagated a second batch of 200 trajectories (at each of three levels of theory) in which the central C 2 =C 3 bond is twisted by 25 • at t = 0. These "activated" trajectories were propagated in the same way and analyzed separately.