Exploring Renner-Teller induced quenching in the reaction H(2S)+NH(a 1Delta): A combined experimental and theoretical study

Experimental rate coefficients for the removal of NH(aΔ1) and ND(aΔ1) in collisions with H and D atoms are presented; all four isotope combinations are considered: NH+H, NH+D, ND+H, and ND+D. The experiments were performed in a quasistatic laser-flash photolysis/laser-induced fluorescence system at low pressures. NH(aΔ1) and ND(aΔ1) were generated by photolysis of HN3 and DN3, respectively. The total removal rate coefficients at room temperature are in the range of (3–5)×1013cm3mol−1s−1. For two isotope combinations, NH+H and NH+D, quenching rate coefficients for the production of NH(XΣ−3) or ND(XΣ−3) were also determined; they are in the range of 1×1013cm3mol−1s−1. The quenching rate coefficients directly reflect the strength of the Renner-Teller coupling between the A″2 and A′2 electronic states near linearity and so can be used to test theoretical models for describing this nonadiabatic process. The title reaction was modeled with a simple surface-hopping approach including a single parameter, which wa...