Dynamics Study on an Interpolated Potential Energy Surface of the Imidogen with Hydroxyl Radical Reaction

A goal of chemical dynamics is to obtain a microscopic picture of how energy flows as atoms move during the course of a chemical reaction [1]. For this purpose, in this work, semi-classical dynamics simulation of the HN(T)+OH(D) reaction on an interpolated ab initio potential energy surface (PES) has been carried out. A global ab initio interpolated PES for the title reaction is constructed using the GROW package [2]. An important aspect of the Grow methodology is monitoring the derived dynamical quantities as points are added to the ab initio data set defining the interpolation. Dynamics of the reaction is investigated on the ground state of the potential energy surface (PES) based on B3LYP calculations. H2O, HNO products and two stable wells trans-HNOH and H2NO were classically observed over the range of relative translational energy (10.5 to 157.5 kJmol-1). The reaction probabilities and reactive cross sections for different channels are reported. The total reaction cross section of the title reaction has been calculated and fitted to an exponential model. Quasiclassical trajectory (QCT) studies on lowest doublet surface shows that the total reaction rate constant is close to the experimental rate constant obtained at lower temperatures (24.5 Lmol-1s-1 at 300K).