Ad. Isaacson, HARMONIC AND ANHARMONIC RATE CONSTANTS AND TRANSMISSION COEFFICIENTS OBTAINED FROM AB-INITIO DATA, The Journal of chemical physics, 107(10), 1997, pp. 3832-3839
Recent ab initio information of Kraka and Dunning on the reaction OH+H
-2-->H2O+H is used to construct a potential energy surface in the vici
nity of the reaction path. The resultant energy surface reproduces the
ab initio reactant and product properties and provides a good fit to
the nb initio data in the interaction region. Anharmonic vibrational e
nergy levels involving the bound degrees of freedom orthogonal to the
reaction coordinate are obtained using perturbation theory through sec
ond order for cubic terms and first order for quartic terms, with reso
nance effects removed. These energy levels are used in the calculation
of transmission coefficients and thermal rate constants over the temp
erature range from 200 to 2400 It. The results are compared with those
obtained from harmonic vibrational energy levels. (C) 1997 American I
nstitute of Physics.