Liu Yang, Li Jun, Felker Peter M, Bačić Zlatko
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 401331, China.
Phys Chem Chem Phys. 2021 Mar 28;23(12):7101-7114. doi: 10.1039/d1cp00865j. Epub 2021 Mar 22.
The interaction between HCl and HO is of considerable theoretical and experimental interest due to its important role in atmospheric chemistry and understanding the onset of the dissociation of HCl in water. In this work, the HCl-HO complex is quantitatively characterized in two ways. First, we report a new full-dimensional potential energy surface (PES) for the HCl + HO system. The nine-dimensional (9D) PES is based on circa 43 000 ab initio points calculated at the level of CCSD(T)-F12a/AVTZ with the basis set superposition error correction using the permutation invariant polynomial-neural network method, which can accurately and efficiently reproduce the geometries, energies, frequencies of the complex of HCl with HO, as well as the relevant minimum energy path. Next, we present the results of the first fully coupled 9D quantum calculations of the intra- and intermolecular vibrational states of the HCl-HO dimer, performed on the new PES. They employ the highly efficient bound-state methodology previously used to compute accurately the rovibrational level structure of the HO/DO-CO and HDO-CO complexes [P. M. Felker and Z. Bačić, J. Chem. Phys., 2020, 153, 074107; J. Phys. Chem. A, 2021, 125, 980]. The 9D calculations characterize the vibrationally averaged nonplanar ground-state geometry of the HCl-HO complex, the intramolecular vibrational fundamentals of both HO and HCl moieties, and their frequency shifts, as well as the low-energy intermolecular vibrational states in each of the intramolecular vibrational manifolds and the effects of the coupling between the two sets of modes. The calculated properties of the HCl-HO dimer are in excellent agreement with the available spectroscopic data. The 9D computed dimer binding energy D of 1334.63 cm agrees extremely well with the experimental D equal to 1334 ± 10 cm [B. E. Casterline and A. K. Mollner and L. C. Ch'ng and H. Reisler, J. Chem. Phys., 2010, 114, 9774]. Moreover, the ground-state expectation value of the out-of-plane bend angle of HO, 33.80°, and the computed HCl stretch frequency shift, -157.9 cm, both from the 9D calculations, are in very good accord with the corresponding experimental values.
HCl与HO之间的相互作用在大气化学中具有重要作用，并且对于理解HCl在水中的解离起始过程具有重要意义，因此在理论和实验方面都备受关注。在本工作中，我们通过两种方式对HCl-HO复合物进行了定量表征。首先，我们报道了一种针对HCl + HO体系的全新全维势能面（PES）。该九维（9D）PES基于大约43000个从头算点，这些点是在CCSD(T)-F12a/AVTZ水平下计算得到的，并使用置换不变多项式-神经网络方法进行基组叠加误差校正，该方法能够准确且高效地再现HCl与HO复合物的几何结构、能量、频率以及相关的最小能量路径。接下来，我们展示了在新的PES上对HCl-HO二聚体的分子内和分子间振动态进行的首次全耦合9D量子计算结果。这些计算采用了先前用于精确计算HO/DO-CO和HDO-CO复合物的振转能级结构的高效束缚态方法[P. M. Felker和Z. Bačić，《化学物理杂志》，2020年，第153卷，074107；《物理化学杂志A》，2021年，第125卷，980]。9D计算表征了HCl-HO复合物振动平均的非平面基态几何结构、HO和HCl部分的分子内振动基频、它们的频率位移，以及每个分子内振动流形中的低能分子间振动态和两组模式之间耦合的影响。计算得到的HCl-HO二聚体的性质与现有的光谱数据非常吻合。9D计算得到的二聚体结合能D为1334.63 cm，与实验值D等于1334 ± 10 cm [B. E. Casterline、A. K. Mollner、L. C. Ch'ng和H. Reisler，《化学物理杂志》，2010年，第114卷，9774]极为吻合。此外，9D计算得到的HO平面外弯曲角的基态期望值为33.80°，以及计算得到的HCl伸缩频率位移为-157.9 cm，都与相应的实验值非常一致。
