LAUSR

The tunneling reaction H 2 + D − → HD + H − was studied in a recent experimental work at low temperatures (10, 19, and 23 K) by Endres et al. [Phys. Rev. A 95, 022706 (2017)]. An upper limit of the rate coefficient was found to be about 10 −18 cm 3 /s. In the present study, reaction probabilities are determined using the ABC program developed by Skouteris et al. [Comput. Phys. Commun. 133, 128 (2000)]. The probabilities for ortho-H 2 and para-H 2 in their ground rovibrational states are obtained numerically at collision energies above 50 meV with the total angular momentum J = 0–15 and extrapolated below 50 meV using a WKB approach. Thermally averaged rate coefficients for ortho-and para-H 2 are obtained; the largest one, for ortho-H 2 , is about 3.1 × 10 −20 cm 3 /s, which agrees with the experimental results.