To describe the photoexcitation leading to central double bond rotation, we chose a minimal active space consisting of the two π bonded orbitals on the two central carbon atoms. Electron correlation was computed to the CISD level. During MD, the active space was tracked by an overlap criterion so that the molecular orbitals retain their character, to a threshold of at least 70 percent overlap with previous active space. The time step of nuclear motion was 0.5fs for ground state sampling simulations, or 0.1fs for most surface-hopping simulations. For motor N, which has more atoms and slower calculations, we increased the surface-hopping timestep to 0.2fs. We found the 0.2fs simulation results of Motor N to be similar to 0.1fs results of Motor N.