Fig. 3: The photochemical process.

a Sketch of the S₁ and S₀ PES along the reaction coordinate(s) with the quantum yield due to Set A. We represented the structures of the chromophore at the beginning of the simulation, at the time of the S₁ → S₀ transition, and at the end of the simulation. The main hydrogen bonds involving the D-ring are highlighted. b Correlation between the dihedral angles D5 and D6. All reactive trajectories from Set A are shown using blue lines for trajectories running on S₁, and red lines for those on S₀. The density distribution is shown at the starting conditions, at the S₁ → S₀ hop, and at the end of the simulation. c Time evolution of the electronic state populations evaluated as the fraction of trajectories running on the given state at the given time for both Set A and Set B, which are the mean values, with their 95% confidence intervals. Black line: fit of the S₁ population according to an exponential function (Supplementary Methods 3). d Representative reactive and non-reactive SH trajectories from Set A and Set B. Green stars represent the S₁-to-S₀ transition. Source data are available in the Zenodo repository⁸⁹.