In the detailed analysis performed on model A, we observed in Fig. that even though the major contribution to the potential barrier forming at q = 0 comes from ε geo (q, R,t), also ε V PEN (q, R,t) presents a barrier. Indeed, such a smaller barrier has some effect on the marginal photon density reconstructed from the distribution of CTMQC trajectories in comparison to MTE and TSH. In Fig. , we report at times t = 0, 270, 540 a.t.u. the histograms calculated from the distributions of trajectories aiming to reproduce the marginal density along q with CTMQC (in blue, top panels), MTE (in red, middle panels) and TSH (in orange, bottom panels); the histograms are compared to the QD photonic marginal densities (black lines). All trajectory-based methods fail in reproducing the correct splitting of the density, thus underestimating the photon-emission process, even though at the final time reported in the figure, CTMQC shows the lowest presence of trajectories at q = 0, probably due to the presence of the small barrier in ε V PEN (q, R,t). Such an effect is not, however, sufficient for producing a complete splitting of the density.