College of Science, Zhejiang University of Technology, Hangzhou, Zhejiang, 310023, China.
College of Mechanical Engineering, Shanghai University of Engineering Science, Shanghai, 201620, China.
Sci Rep. 2020 May 22;10(1):8539. doi: 10.1038/s41598-020-65475-2.
The impact of the dispersion and electron correlation effects on describing quantum mechanics/molecular mechanics (QM/MM) interactions in QM/MM molecular dynamics (MD) simulations was explored by performing a series of up to 2 ns QM/MM MD simulations on the B states of the myoglobin-carbon monoxide (MbCO) system. The results indicate that both dispersion and electron correlations play significant roles in the simulation of the ratios of two B states (B/B), which suggests that the inclusion of the electron correlation effects is essential for accurately modeling the interactions between QM and MM subsystems. We found that the QM/MM interaction energies between the CO and the surroundings statistically present a linear correlation with the electric fields along the CO bond. This indicates that QM/MM interactions can be described by a simple physical model of a dipole with constant moment under the action of the electric fields. The treatment provides us with an accurate and effective approach to account for the electron correlation effects in QM/MM MD simulations.
通过对肌红蛋白-一氧化碳（MbCO）体系 B 态进行长达 2 纳秒的量子力学/分子力学（QM/MM）分子动力学（MD）模拟，研究了在 QM/MM MD 模拟中描述量子力学/分子力学（QM/MM）相互作用时，弥散和电子相关效应对描述的影响。结果表明，弥散和电子相关效应对模拟两个 B 态（B/B）的比值都有重要作用，这表明在准确模拟 QM 和 MM 子系统之间的相互作用时，纳入电子相关效应是至关重要的。我们发现，CO 和周围环境之间的 QM/MM 相互作用能与 CO 键沿线上的电场呈统计线性相关。这表明 QM/MM 相互作用可以用在电场作用下具有恒定偶极矩的简单物理模型来描述。该处理方法为我们提供了一种准确有效的方法，可在 QM/MM MD 模拟中考虑电子相关效应。
