In Fig. the TDVP offers a complementary perspective on the nuclear dynamics to the TDPES, and, in the used gauge, it is identified with the nuclear momentum field. As for the TDPES, the TDVP is only shown in regions where the nuclear density is larger than 10 -7 . At t = 10 fs (left panel) the TDVP is small in magnitude because the dynamics starts with zero average momentum, and appears symmetric in the ϕ direction with respect to ϕ = 0. This feature is maintained all along the simulated dynamics, as the nuclear density moves symmetrically towards the CIs. The TDVP reported in all panels in Fig. changes sign in the ϕ direction at ϕ = 0.