Modelling of reagent reorientation and tunneling in the activated exchange reaction N(2D) + H2 → NH + H

Abstract

The Linear Transformation Model, recently proposed by the authors, describes the crossing of an early barrier in the case where a significant reorientation of the reagents occurs en route to the barrier top. The topology of the barrier as well as the mass combination considered are typically those involved in the title reaction. The model, however, was established within the framework of classical mechanics. It is thus not applicable to the case where tunneling is responsible for most or all of the reactivity. The present work aims at removing this shortcoming by incorporating a tunneling correction into the model. The reaction cross section found for the title reaction at a collision energy below the barrier height is in very good agreement with recent quantum mechanical calculations.