Department of Chemistry and Biochemistry, University of Arkansas, Fayetteville, Arkansas 72701, USA.
J Chem Phys. 2019 Nov 14;151(18):184501. doi: 10.1063/1.5124811.
Pairwise additive model potentials for CO were developed by fitting to gradients computed with the local second order Møller Plesset Perturbation theory (LMP2) method, with and without consideration of 3-body dispersion using adaptive force matching. Without fitting to experiments, all models gave good predictions of properties of CO, such as the density-temperature diagram, diffusion constants, and radial distribution functions. For the prediction of vibrational spectra, the inclusion of a bond-bond coupling term has been shown to be important. The CO models developed only have pairwise additive terms, thus allowing microsecond time scale simulations to be performed with practical computational cost. LMP2 performed significantly better than second order Møller Plesset Perturbation theory (MP2) for the development of the CO model. This is attributed to the appreciable reduction in the basis set superposition error when the localized method was used. It is argued that LMP2 is a more appropriate method than MP2 for force matching for systems where the basis set superposition error is large.
采用自适应力匹配，通过拟合基于局域二级 Møller-Plesset 微扰理论 (LMP2) 方法计算的梯度，开发了 CO 的两两加和模型势。所有模型都没有拟合实验，却对 CO 的性质（如密度-温度图、扩散常数和径向分布函数）做出了很好的预测。对于振动光谱的预测，证明了包含键键耦合项很重要。所开发的 CO 模型仅具有两两加和项，因此允许以实际的计算成本进行微秒时间尺度的模拟。对于 CO 模型的开发，LMP2 的性能明显优于二级 Møller-Plesset 微扰理论 (MP2)。这归因于当使用局域方法时，基组叠加误差有明显减少。有人认为，对于基组叠加误差较大的系统，LMP2 是比 MP2 更适合的力匹配方法。
