Pawlak Mariusz, Żuchowski Piotr S, Jankowski Piotr
Faculty of Chemistry, Nicolaus Copernicus University in Toruń, Gagarina 7, 87-100 Toruń, Poland.
Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudzia̧dzka 5, 87-100 Toruń, Poland.
J Chem Theory Comput. 2021 Feb 9;17(2):1008-1016. doi: 10.1021/acs.jctc.0c01122. Epub 2021 Jan 21.
We present very accurate theoretical results of Penning ionization rate coefficients of the excited metastable helium atoms (He(2S) and He(2S)) colliding with the hydrogen isotopologues (H, HD, D) in the ground and first excited rotational and vibrational states at subkelvin regime. The calculations are performed using the current best interaction energy surface, which takes into account the nonrigidity effects of the molecule. The results confirm a recently observed substantial quantum kinetic isotope effect (. 2014, 6, 332-335) and reveal that the change of the rotational or vibrational state of the molecule can strongly enhance or suppress the reaction. Moreover, we demonstrate the mechanism of the appearance and disappearance of resonances in Penning ionization. The additional model computations, with the morphed interaction energy surface and mass, give better insight into the behavior of the resonances and thereby the reaction dynamics under study. Our theoretical findings are compared with all available measurements, and comprehensive data for prospective experiments are provided.
我们给出了亚开尔文温度下，处于基态以及第一激发转动和振动态的氢同位素分子（H、HD、D）与激发的亚稳态氦原子（He(2S)和He(2S)）碰撞时潘宁电离速率系数的非常精确的理论结果。计算使用了当前最佳的相互作用能面，该能面考虑了分子的非刚性效应。结果证实了最近观察到的显著的量子动力学同位素效应（. 2014, 6, 332 - 335），并表明分子转动或振动态的变化可以强烈增强或抑制反应。此外，我们展示了潘宁电离中共振出现和消失的机制。通过变形的相互作用能面和质量进行的额外模型计算，能更好地洞察共振行为，从而了解所研究的反应动力学。我们将理论结果与所有可用测量值进行了比较，并提供了前瞻性实验的综合数据。
