从机器学习的微观模拟中推断Onsager系数.
Kaihua Zhang1, Shuanhu Qi2, Yongzhi Ren3,4,5
1School of Chemistry, Beihang University, Beijing 100191, China.
The Journal of chemical physics
|January 15, 2025
概括
我们开发了一种机器学习方法,从分子模拟中提取动态密度函数理论 (DDFT) 的Onsager系数. 这种方法通过直接计算这个关键参数来提高聚合物动态建模的准确性.
科学领域:
- 聚合物科学 聚合物科学
- 计算材料科学科学 计算材料科学
- 统计力学 统计力学
背景情况:
- 动态密度函数理论 (DDFT) 是一个强大的多尺度建模方法,用于聚合物动态.
- DDFT的准确性受到其唯一自由参数 - - Onsager系数 - - 的经验推导的限制.
- 建立基于粒子的模拟与粗粒度模型之间的桥梁仍然是一个挑战.
研究的目的:
- 开发一种新的机器学习工作流程,用于从分子模拟中直接提取Onsager系数.
- 提高DDFT在建模聚合物动态中的准确性和适用性.
- 在聚合物融中建立动态相关性和系统参数之间的联系.
主要方法:
- 开发了一个基于DDFT的普通微分方程网络.
- 该网络使用来自布朗动力学 (BD) 模拟聚合物密度演变的数据进行训练.
- 通过将网络与BD模拟结果相匹配来提取Onsager系数.
主要成果:
- 机器学习工作流成功提取了Onsager系数.
- 使用提取的Onsager系数的DDFT模型准确地复制了在双块共聚合物中叶片过渡的BD模拟结果.
- 在Onsager系数,动态相关性 (强度和长度) 和像Flory-Huggins相互作用参数这样的系统参数之间发现了强烈的相关性.
结论:
- 拟议的机器学习方法提供了一种可靠的自下而上的方法来确定DDFT中的Onsager系数.
- 这项工作在聚合物系统中建立了动态相关性和热力学参数之间的直接联系.
- 开发的框架提供了一种途径,可以将详细的分子模拟与非平衡系统的粗粒度场理论相结合.
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