An analytic global potential energy surface of the CsH2 system and the dynamic calculations of the H + CsH reaction

Abstract

ABSTRACT Based on 17,326 ab initio points, a global potential energy surface (PES) of the ground state of the CsH2 system was constructed using the neural network method. In ab initio calculations, the AVQZ basis set was used for the H atom, the def2-QZVP basis set was adopted for the Cs atom, and a multi-reference configuration interaction method was employed. The topographical characteristics of the newly developed PES were discussed in detail and no wells or barriers were detected. In addition, the dynamical calculations of the H + CsH reaction were performed using the time-dependent wave packet method, based on the new PES. Dynamics properties, such as reaction probability, integral cross section and differential cross-section were examined. The differential cross-section results indicated that the forward abstraction mechanism dominated the abstraction channel, and the ‘rebound' reaction mechanism played a primary role in the exchange channel. Highlights Using the PIP-NN method, A global potential energy surface for the ground state of the CsH2 system was built based on 17,326 ab initio points. Dynamic calculations for the abstraction and exchange channels of the H + CsH reaction were performed using the time-dependent wave packet method and the dynamic properties of these two channels were discussed in detail. The direct abstraction mechanism plays a dominant role in the abstraction channel and the ‘rebound' mechanism dominates the exchange channel.