The rate constants for the H+H2 reaction and its isotopic analogs at low temperatures: Wigner threshold law behavior
- 1 June 1987
- journal article
- research article
- Published by AIP Publishing in The Journal of Chemical Physics
- Vol. 86 (11) , 6133-6139
- https://doi.org/10.1063/1.452453
Abstract
Variational transition‐state theory rate constants for the H+H2 reaction and its isotopic analogs at very low temperatures have been calculated using the LSTH potential surface. The Wigner threshold law is found to hold quantitatively below 1 K and to within 34% on average at 5 K. The transition‐state theory rate constants are found to be consistent with the requirements of the Wigner threshold law provided that a tunneling probability having the correct threshold behavior is used in calculating the transmission coefficient. Using these calculated rate constants, decay rates of H and D atoms in solid H2, D2, and HD were estimated and compared with experiment. The good agreement found suggests that these decays occur through quantum mechanical tunneling exchange reactions.Keywords
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