Résumé
We present a quantum dynamics method based on the propagation of interacting quan-tum trajectories to describe both adiabatic and nonadiabatic processes within the sameformalism. The idea originates from the work of Poirier [Chem. Phys. 370 4–14 (2010)]and Schiff and Poirier [J. Chem. Phys. 136 031102 (2012)] on quantum dynamics with-out wavefunctions. It consists in determining the quantum force arising in the Bohmianhydrodynamic formulation of quantum dynamics using only information about quan-tum trajectories. The particular time-dependent propagation scheme proposed hereresults in very stable dynamics. Its performance is discussed by applying the methodto analytical potentials in the adiabatic regime, and by combining it with the exactfactorization method in the nonadiabatic regime.