Abstract

Smoothed molecular dynamics (SMD) method is an efficient mesoscopic method by introducing one set of background mesh and mapping procedure into the molecular dynamics (MD) flowchart. The motion equations are established on the mesh nodes. SMD allows much larger time-step size compared to MD. In this paper, the critical time-step size of SMD is thoroughly analyzed, and the effects of mesh cell size, mapping functions and potential functions are studied. An efficiency improvement by reconstructing atomic force field (ReAFF) for SMD, namely the ReAFF-SMD method, is proposed. The atom sampling and the field construction schemes in ReAFF-SMD method are discussed in detail. An efficient moving-window technique is also developed for adaptively coupling MD and ReAFF-SMD method. The proposed method is then validated with several typical examples of various types of loadings and materials.

中文翻译：

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平滑分子动力学方法效率的关键评估和改进

摘要

平滑分子动力学（SMD）方法是一种高效的介观方法，通过在分子动力学（MD）流程图中引入一组背景网格和映射程序。运动方程在网格节点上建立。与 MD 相比，SMD 允许更大的时间步长。本文深入分析了SMD的临界时间步长，研究了网格单元尺寸、映射函数和势函数的影响。提出了一种通过重构SMD原子力场(ReAFF)来提高效率的方法，即ReAFF-SMD方法。详细讨论了ReAFF-SMD方法中的原子采样和场构建方案。还开发了一种有效的移动窗口技术，用于自适应耦合 MD 和 ReAFF-SMD 方法。然后用各种类型的载荷和材料的几个典型示例来验证所提出的方法。