Dynamics of the C(¹D)+H₂ reaction: A comparison of crossed molecular beam experiments with quantum mechanical and quasiclassical trajectory calculations on the first two singlet (1¹A′ and 1¹A″) potential energy surfaces

Abstract

The contribution of the first excited 1¹A″ state potential energy surface (PES) to the reactivity of the C(¹D)+H₂ system has been examined by comparing the simulations obtained with the theoretical state-to-state differential cross sections (DCSs) with experimental data from cross molecular beam experiments. The calculations were carried out using the quantum scattering and quasiclassical trajectory calculations on the ground and first excited PESs, and the DCSs were convoluted with the various apparatus functions in order to simulate the experimental laboratory angular distributions and time-of-flight distributions. It was expected that the participation of the excited PES could solve the relatively minor discrepancies resulting from the comparison between the experimental data and the simulations using the DCSs obtained on the ground state PES. Nevertheless, the addition of the contribution of the excited 1¹A″ PES worsens the agreement with the experimental results.

Keywords:

• reaction dynamics
• reactive scattering
• crossed molecular beams
• photodissociation dynamics
• chemical kinetics

Acknowledgements

It is our greatest pleasure to dedicate this article to Professor Hans-Joachim Werner on his 60th anniversary. His contributions to Reaction Dynamics via state-of-the-art electronic structure calculations of potential energy surfaces have been a source of inspiration for many researchers in the field. In addition, those who have had the opportunity and privilege of collaborating with him have enjoyed his human qualities and love for top-quality research. The authors would like to thank Dr. Dimitris Skouteris for helpful discussions on the symmetry of the electronic states. NB and PC acknowledge financial support from the Italian MIUR (Ministero Istruzione Università Ricerca) under the project PRIN (2007H9S8SW_004). FJA and LB acknowledge financial support from the Spanish Ministry of Education and Science (grant CTQ2008-02578). The QM calculations were performed using HPC resources from GENCI [CCRT/CINES/IDRIS] (grant 2009 [i2009082031]).