The formation of the trans conformer is reproduced by the quantum trajectories (lilac) in extremely good agreement with exact results, indicating that a trajectorybased representation of nuclear dynamics for this retinal model is adequate to study the trans photo-product formation after excitation by light. However, TDVP results slightly deviate from the reference towards the end of the simulated dynamics, due to numerical errors in the time integration of Eq. ( ) when the TDVP develops a highly oscillatory behavior (see Fig. at time 100 fs).