Finally, to ultimately confirm the molecular rotary motor character of the proposed PFCN system, we have performed nonadiabatic molecular dynamics (NAMD) simulations for the photoexcited S R form relaxation, details of which have been described more extensively in the SI (Section 4). In the course of the simulations, an ultrafast, single-exponential decay of the excited-state population has been observed (Figure (a)), with fitted half-lifetime of about 3.6 ps, which stays in line with timescales observed in some second-generation motors. Analysis of S 1 → S 0 relaxation points (Figure (b)) revealed that the leading deactivation mechanism involves funneling through the lower-energy, MECI in conical intersection. In addition, some more extended relaxation area has been also observed between MECI in and MECI out , corresponding to central, low energy-gap S 1 PES region identified previously along the optical-step motor reaction path (Figure ).