In the chosen gauge for the QD calculations, the R-TDVP is the nuclear momentum field and the q-TDVP is the photon momentum field. Thus, they provide additional insights into the photon-nuclear dynamics, complementing the information derived from the TDPES. However, the details of the photon momentum filed are obscured in the total TDVP due to the chosen larger mass associated to the nuclear degree of freedom than that of the photon displacement (20000 times larger). This causes the TDVP in the R-direction to be dominant. Therefore, rather than showing the momentum field, in Fig. we show the velocity field: the color map provides information about the modulus of the velocity vector field while the unit-vectors about its direction.