恒温不平衡系统:在指令扰动下的系统的热能约束
J P Martínez Cordeiro1, N R Aluru1
1Walker Department of Mechanical Engineering, Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, Texas 78712, USA.
The Journal of chemical physics
|March 26, 2025
概括
只有当扰动小时,平衡恒温器才适用于非平衡分子动力学模拟. 本研究对干扰进行了分类,并分析了指令类型,为复杂系统中合理使用恒温器提供了限制.
科学领域:
- 计算物理 计算物理
- 统计力学 统计力学
- 化学物理 化学物理
背景情况:
- 平衡恒温器通常用于非平衡分子动力学 (NEMD) 模拟.
- 这种做法的理论理由,特别是关于波动-散流定理的理论,经常被忽视或被错误地应用.
研究的目的:
- 在NEMD模拟中重新检查平衡恒温器的有效性.
- 在分子动力学中对外部干扰进行分类,并分析较少研究的指导干扰.
- 建立在扰乱系统中合理使用平衡恒温器的标准.
主要方法:
- 对外部干扰进行分类,分为响应式 (施加力) 和指令式 (施加轨迹) 模型.
- 对指令扰动对简单扰动恒温器系统的影响分析.
- 在Lennard-Jones流体中应用一个扰动的两点波器和一个驱动的粒子,以接近极限.
主要成果:
- 在NEMD中,平衡恒温器的合理性依赖于微小的干扰,这些干扰极小地改变了系统的平衡行为.
- 指令干扰,虽然研究较少,但在NEMD中变得越来越重要.
- 对于特定的扰乱系统,我们得出了合理平衡温度控制器使用的极限的近似值.
结论:
- 在NEMD模拟中使用平衡恒温器需要仔细考虑扰动的大小和类型.
- 对指令扰动的进一步研究对于推进NEMD至关重要.
- 这项工作为理解在不平衡模拟中平衡恒温器的局限性和适用性提供了基础.
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