Song Qingfei, Zhang Qiuyu, Meng Qingyong
School of Chemistry and Chemical Engineering, Northwestern Polytechnical University, West Youyi Road 127, 710072 Xi'an, China.
J Chem Phys. 2020 Apr 7;152(13):134309. doi: 10.1063/1.5143544.
In this work, Gaussian process regression (GPR) for fitting a high-dimensional potential energy surface (PES) is revisited and implemented to construct the PES of OH + HO → O + HO. Using mixed kernel function and optimized distribution of the training database, only ∼3 × 10 energy points are needed to approach convergence, which implies the power of GPR in saving lots of computational cost. Moreover, the convergence of the GPR PES is inspected, leading to discussions on the advantages of the GPR fitting approach. By the segmented strategy [Meng et al., J. Chem. Phys. 144, 154312 (2016)], a GPR PES with a fitting error of ∼21 meV is constructed using ∼4600 energy points at the CCSD(T)-F12a/aug-cc-pVTZ level. The rate coefficients are then computed through the ring-polymer molecular dynamics (RPMD) method. An agreement between the present RPMD calculations and the previous observations is found, implying the accuracy of the present calculations. Moreover, the unusual feature of the Arrhenius curve is interpreted by a coupled harmonic oscillator model [Q. Meng, J. Phys. Chem. A 122, 8320 (2018)] together with a simple kinetics model.
在这项工作中，我们重新审视并实现了用于拟合高维势能面（PES）的高斯过程回归（GPR），以构建OH + HO → O + HO的PES。使用混合核函数和优化的训练数据库分布，仅需约3×10个能量点即可接近收敛，这意味着GPR在节省大量计算成本方面的强大能力。此外，我们检查了GPR PES的收敛性，从而讨论了GPR拟合方法的优点。通过分段策略[Meng等人，《化学物理杂志》144, 154312 (2016)]，在CCSD(T)-F12a/aug-cc-pVTZ水平上使用约4600个能量点构建了拟合误差约为21 meV的GPR PES。然后通过环聚合物分子动力学（RPMD）方法计算速率系数。发现当前的RPMD计算结果与先前的观测结果一致，这意味着当前计算的准确性。此外，通过耦合谐振子模型[Q. Meng，《物理化学杂志A》122, 8320 (2018)]以及一个简单的动力学模型对阿仑尼乌斯曲线的异常特征进行了解释。
