Reaction dynamics for the N(2D)+ H2 reaction

Abstract

The dynamics of the N(²D)+ H₂→ 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 is used for the quantum scattering calculations. The quantum calculations are carried out only for the total angular momentum J= 0. The J-shifting approximation is used to compute reaction cross-sections and thermal rate constants. Both the quantum and quasiclassical calculations are found to reproduce the experimental vibrational distribution of the product NH at 300 K. For the thermal rate constants, an excellent agreement is obtained between the quantum results and the experimental results, although the quantum rate constants are restricted to the N(²D)+ H₂(v_i= 0,j_i= 0) reaction. On the other hand, it is shown that the quasiclassical trajectory calculations give larger rate constants than the experimental ones.