Wang Xiaohong, Houston Paul L, Bowman Joel M
Department of Chemistry, and Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, GA 30322, USA.
School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Philos Trans A Math Phys Eng Sci. 2017 Apr 28;375(2092). doi: 10.1098/rsta.2016.0194.
We report a new global potential energy surface (PES) for HCO, based on precise fitting of roughly 67 000 MRCI/cc-pVTZ energies. This PES describes the global minimum, the - and -HCOH isomers, and barriers relevant to isomerization, formation of the molecular (H+CO) and radical (H+HCO) products, and the loose so-called roaming transition-state saddle point. The key features of the PES are reviewed and compared with a previous PES, denoted by PES04, based on five local fits that are 'stitched' together by switching functions (Zhang 2004 , 8980-8986 (doi:10.1021/jp048339l)). Preliminary quasi-classical trajectory calculations are performed at the total energy of 36 233 cm (103 kcal mol), relative to the HCO global minimum, using the new PES, with a particular focus on roaming dynamics. When compared with the results from PES04, the new PES findings show similar rotational distributions, somewhat more roaming and substantially higher H vibrational excitation.This article is part of the themed issue 'Theoretical and computational studies of non-equilibrium and non-statistical dynamics in the gas phase, in the condensed phase and at interfaces'.
我们基于对约67000个MRCI/cc-pVTZ能量的精确拟合，报告了一种新的HCO全局势能面（PES）。该势能面描述了全局最小值、-和-HCOH异构体，以及与异构化、分子（H+CO）和自由基（H+HCO）产物形成相关的势垒，还有所谓的松散漫游过渡态鞍点。本文回顾了该势能面的关键特征，并与之前的一个势能面（记为PES04）进行了比较，后者基于通过切换函数“拼接”在一起的五个局部拟合（Zhang 2004, 8980 - 8986 (doi:10.1021/jp048339l)）。使用新的势能面，在相对于HCO全局最小值的36233 cm（103 kcal mol）总能量下进行了初步的准经典轨迹计算，特别关注漫游动力学。与PES04的结果相比，新势能面的研究结果显示出相似的转动分布、更多一点的漫游以及更高的H振动激发。本文是主题为“气相、凝聚相和界面中非平衡和非统计动力学的理论和计算研究”这一特刊的一部分。
