Systematic evaluation and refinement of existing all‐atom force fields for the simulation of liquid acetonitrile
Systematic evaluation and refinement of existing all‐atom force fields for the simulation of liquid acetonitrile
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用于模拟液体乙腈的现有全原子力场的系统评估和细化
DOI：
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发表时间：
2018
影响因子：
3
通讯作者：
Leila Tohidifar
中科院分区：
文献类型：
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作者：
M. H. Kowsari;Leila Tohidifar
分子动力学（MD）模拟研究的可靠性主要取决于外加力场的准确性。与一些潜在模型合理预测乙腈（ACN）热力学性质的能力不同，与实验值相比，模拟的动力学性质（如自扩散）通常被低估。本文着重对ACN中几种可用的全原子力场进行了评价和改进，并提出了一种改进的柔性六位势模型。主要的修饰与氢原子的分子间LJ参数（σ和ε）的降低有关，特别是ε，显著影响了动力学行为。此外，对腈碳和氮原子的σ和α的调整有助于达到最佳效果。我们的改进模型在自扩散系数和热力学量上与实验结果非常吻合，并提供了对液体ACN微观结构的定性描述。©2018 Wiley期刊公司
The reliability of a molecular dynamics (MD) simulation study mainly depends on the accuracy of the applied force field. Unlike the ability of some potential models for reasonably predicting the thermodynamic properties of acetonitrile (ACN), simulated dynamical properties such as self‐diffusion are generally underestimated compared to experimental values. The present work focuses on the evaluation and refinement of several available all‐atom force fields for ACN and proposes a refined flexible six‐site potential model. The main modification is related to the reduction of intermolecular LJ parameters (σ and ɛ) for hydrogen atoms, especially ɛ, significantly affecting the dynamical behavior. Besides, the adjustment of σ and ɛ for nitrile carbon and nitrogen atoms helps reach optimum results. Our refined model shows an excellent agreement with the experiment for self‐diffusion coefficient and thermodynamic quantities as well as providing a qualitative description of the microscopic structure of liquid ACN. © 2018 Wiley Periodicals, Inc.