Isotopic effects on stereodynamics for the two reactions: H + LiH+(v = 0, j = 0) → H2 + Li+ and H+ + LiH(v = 0, j = 0) → H2+ + Li

The isotopic effects on stereodynamic properties for the title reactions occurring on the two lowest-lying electronic potential energy surfaces (PESs) of LiH2+ are investigated in detail by means of the quasi-classical trajectory (QCT) method at a collision energy of 0.5 eV, using the ab initio potential energy surfaces (PESs) of Martinazzo et al. (J. Chem. Phys., 2003, 119, 11241). The corresponding reactions comprise: (i) H/D/T + LiH+ → HH/HD/HT + Li+ and H + LiH+/LiD+/LiT+ → HH/HD/HT + Li+; (ii) H+/D+/T+ + LiH → HH+/HD+/HT+ + Li and H+ + LiH/LiD/LiT → HH+/HD+/HT+ + Li. Differential cross sections (DCSs) and alignments of the product rotational angular momentum for all of these reactions are reported. The results illustrate that the reason for the abnormal behavior of the DCSs for the title reactions reported in the previous work is ascribed to the sensitive role of the projectile atomic mass, and indicate that the long-range interactions play a more important role than the mass factor in ion–molecule reactions. The current topic for this special mass combination system shows some new features of the stereodynamics differing from the previous studies for “typical” mass-combination reactions.