Figure shows the electronic state populations as functions of time obtained with quantum dynamics. As we can observe, after an initial wavepacket excitation from S 0 to S 1 with sufficient kinetic energy to reach the S 1 /S 2 conical intersection, the S 2 state gets rapidly populated within the first few femtoseconds. Some population remains in S 1 , either because it does not have enough energy to reach S 2 or because it is able to overcome the S 1 energy barrier towards the dissociative path. In S 2 , one portion of the photo-excited wavepacket goes back towards the S 1 minimum and we observe a decrease in the S 2 population (red curve) which reaches a minimum at around 10 fs. At the same time, another portion of the S 2 wavepacket funnels down S 1 and access the dissociative region. We observe a slow rise of the ground state population (blue curve) from around 16 fs, which indicates that the S 1 wavepacket reaches the second conical intersection S 0 /S 1 . As the dynamics proceeds, the population of S 1 stabilizes towards 0.6, suggesting that the corresponding wavepacket either remains trapped at the minimum of S 1 or is moving in the dissociative portion of the PES; at the same time, the population of S 0 increases and that of S 2 decreases.