REACTION DYNAMICS FOR THE N(D-2)+H-2 REACTION

The dynamics of the N(D-2) + H-2 --> NH + H reaction has been studied by both accurate three-dimensional quantum scattering calculations and quasiclassical trajectory calculations. The potential-energy surface which has recently been developed on the basis of ab initio molecular- orbital calculations is employed. A hyperspherical coordinate system i s used for the quantum scattering calculations. The quantum calculatio ns are carried out only for the total angular momentum J = 0. The J-sh ifting approximation is used to compute reaction cross-sections and th ermal rate constants. Both the quantum and quasiclassical calculations are found to reproduce the experimental vibrational distribution of t he product NH at 300 K. For the thermal rate constants, an excellent a greement is obtained between the quantum results and the experimental results, although the quantum rate constants are restricted to the N(D -2) + H-2 (v(i) = 0, j(i) = 0) reaction. On the other hand, it is show n that the quasiclassical trajectory calculations give larger rate con stants than the experimental ones.