Quasi-classical trajectory study of the N(2D) + H2 → NH + H and N(2D) + D2 → ND + D reactions: Vector correlation

The vector correlations between products and reagents for the title reactions are investigated by employing the quasi-classical trajectory (QCT) method. A collision energy of 3.8 kcal/mol and an accurate 12A″ state potential energy surface (PES) of [11] are used in calculations. The four generalized polarization-dependent differential cross-sections (PDDCSs) (2π/σ)(dσ00/dωt),(2π/σ)(dσ20/dωt),(2π/σ)(dσ22+/dωt),and(2π/σ)(dσ21-/dωt) are calculated in the center-of-mass frame. The distribution of the angle between k and j′, P(θr), the distribution of the dihedral angle denoting k-k′-j′ correlation, P(ϕr), as well as the angular distribution of product rotational vectors in the form of polar plots P(θr, ϕr) are also calculated. The results indicate that the product rotational angular momentum j′ is not only aligned, but also oriented along the negative direction of y-axis. The isotope effect is revealed and primarily attributed to the difference in mass factor between the two title reactions.