THE DYNAMICS OF THE REACTION OH-2-]HOD+D - CROSSED-BEAM EXPERIMENTS AND QUANTUM-MECHANICAL SCATTERING CALCULATIONS ON AB-INITIO POTENTIAL-ENERGY SURFACES(D)

The dynamics of the reaction OH + D-2 --> HOD + D has been investigate d in a crossed molecular beam experiment at a collision energy of 6.3 kcal/mol. From laboratory product angular and velocity distribution me asurements, center-of-mass product translational energy and angular di stributions were determined. The HOD angular distribution is strongly backward scattered (with respect to the OH direction), which reflects a direct rebound dynamics, and the average fraction of total available energy released into translation is 0.34, indicating a high degree of product internal excitation. These results are compared with the pred ictions of two different ab initio potential energy surfaces within qu antum mechanical scattering calculations based on the rotating bond ap proximation. It is concluded that a new surface, obtained from large s cale high-quality electronic structure calculations, represents a sign ificant improvement with respect to the previous Walch-Dunning-Schatz- Elgersma potential energy surface.