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

Abstract

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 1 2A″ state potential energy surface (PES) of [11] are used in calculations. The four generalized polarization-dependent differential cross-sections (PDDCSs) ( 2 π / σ ) ( d σ 00 / d ω t ) , ( 2 π / σ ) ( d σ 20 / d ω t ) , ( 2 π / σ ) ( d σ 22 + / d ω t ) , and ( 2 π / σ ) ( d σ 21 - / d ω t ) are calculated in the center-of-mass frame. The distribution of the angle between k and j ′, P( θ r ), the distribution of the dihedral angle denoting k – k ′– j ′ correlation, P( ϕ r ), as well as the angular distribution of product rotational vectors in the form of polar plots P( θ r , ϕ r ) 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.