Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (UMR 8112 du CNRS), Observatoire de Paris-Meudon, Université Pierre et Marie Curie, 92195 Meudon Cedex, France.
J Chem Phys. 2013 Nov 28;139(20):204305. doi: 10.1063/1.4832324.
We report the first global potential energy surface (PES) for the X(2)A' ground electronic state of the Si((3)P) + OH(X(2)Π) → SiO(X(1)Σg(+)) + H((2)S) reaction. The PES is based on a large number of ab initio energies obtained from multireference configuration interaction calculations plus Davidson correction (MRCI+Q) using basis sets of quadruple zeta quality. Corrections were applied to the ab initio energies in the reactant channel allowing a proper description of long-range interactions between Si((3)P) and OH(X(2)Π). An analytical representation of the global PES has been developed by means of the reproducing kernel Hilbert space method. The reaction is found barrierless. Two minima, corresponding to the SiOH and HSiO isomers, and six saddle points, among which the isomerization transition state, have been characterized on the PES. The vibrational spectra of the SiOH/HSiO radicals have been computed from second-order perturbation theory and quantum dynamics methods. The structural, energetic, and spectroscopic properties of the two isomers are in good agreement with experimental data and previous high quality calculations.
我们报道了 Si((3)P) + OH(X(2)Π) → SiO(X(1)Σg(+)) + H((2)S) 反应的 X(2)A' 基态的第一个全球势能面 (PES)。该 PES 基于大量使用四重 zeta 质量基组的多参考组态相互作用计算加戴维森修正 (MRCI+Q) 获得的从头算能量。在反应物通道中对从头算能量进行了修正，以正确描述 Si((3)P) 和 OH(X(2)Π) 之间的远程相互作用。通过再生核 Hilbert 空间方法开发了全局 PES 的解析表示。反应被发现没有势垒。在 PES 上已经确定了两个对应于 SiOH 和 HSiO 异构体的最小值和六个鞍点，其中包括异构化过渡态。SiOH/HSiO 自由基的振动光谱是从二阶微扰理论和量子动力学方法计算得到的。两个异构体的结构、能量和光谱性质与实验数据和以前的高质量计算结果非常吻合。
