Rotational cooling efficiency upon molecular ionization: thecase of Li2(a3Σu+) and Li2+(X2Σg+) interactingwith 4He

The low-temperature (up to about 100 K) collisional (de)excitation cross sections are computed using the full coupled-channel (CC) quantum dynamics for both Li₂ and Li₂ ⁺ molecular targets in collision with ⁴He. The interaction forces are obtained from fairly accurate ab initio calculations and the corresponding pseudo-rates are also computed. The results show surprising similarities between sizes of inelastic flux distributions within final states in both systems and the findings are connected with the structural change in the molecular rotor features when the neutral species is replaced by its ionic counterpart.