Non-adiabatic Quantum Dynamics of the Dissociative Charge Transfer He++H2 → He+H+H+

We present the non-adiabatic, conical-intersection quantum dynamics of the title collision where reactants and products are in the ground electronic states. Initial-state-resolved reaction probabilities, total integral cross sections, and rate constants of two H-2 vibrational states, v(0) = 0 and 1, in the ground rotational state (j(0) = 0) are obtained at collision energies E-coll <= 3 eV. We employ the lowest two excited diabatic electronic states of HeH2+ and their electronic coupling, a coupled-channel time-dependent real wavepacket method, and a flux analysis. Both probabilities and cross sections present a few groups of resonances at low E-coll, whose amplitudes decrease with the energy, due to an ion-induced dipole interaction in the entrance channel. At higher E-coll, reaction probabilities and cross sections increase monotonically up to 3 eV, remaining however quite small. When H-2 is in the v(0) = 1 state, the reactivity increases by similar to 2 orders of magnitude at the lowest energies and by similar to 1 order at the highest ones. Initial-state resolved rate constants at room temperature are equal to 1.74 x 10(-14) and to 1.98 x 10(-12) cm(3)s(-1) at v(0) = 0 and 1, respectively. Test calculations for H2 at J(0) = 1 show that the probabilities can be enhanced by a factor of similar to 1/3, that is ortho-H-2 seems similar to 4 times more reactive than para-H-2.