  The low-temperature (up to about 100K) collisional (de)excitation cross
sections are computed using the full coupled-channel (CC) quantum dynamics for
both Li$_2$ and Li$_2^+$ molecular targets in collision with $^4$He. The
interaction forces are obtained from fairly accurate {\it 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.
