In our trajectory simulations, we propagated N tr = 600 Wigner-distributed trajectories starting in the S 1 state, with centers at (0.172459 bohr, 0 • , 0 • ) for the r , θ and φ coordinates, all with zero center momentum. The variances were (0.154449 bohr, 0.183302 • , 0.406143 • ). Periodic boundary conditions were applied to the θ and φ degrees of freedom, with periodicities of 2π and 4π, respectively. The same periodicity was imposed on the centers of the quantum momentum. We used a nuclear and electronic time-step of dt = 0.00024 fs (0.01 /Ha). For the QD simulations, the initial wavepacket is propagated with a time-step of 1 fs in the diabatic representation with the short iterative Lanczos approach 62,63 implemented in ElVibRot. Furthermore, the wavepacket is expanded on the same basis sets as the ones used in Ref [ 45].