论文标题

一种新型的机器学习启用了混合优化框架,以实现模型聚合物的有效且可转移的粗晶

A novel machine learning enabled hybrid optimization framework for efficient and transferable coarse-graining of a model polymer

论文作者

Shireen, Zakiya, Weeratunge, Hansani, Menzel, Adrian, Phillips, Andrew W, Larson, Ronald G, Smith-Miles, Kate, Hajizadeh, Elnaz

论文摘要

这项工作提出了一个新的框架,该框架管理了多层材料的有效,准确和可转移的粗粒(CG)模型的开发。提出的框架结合了两种根本不同的经典优化方法,用于开发粗粒模型参数。即自下而上和自上而下的方法。这是通过将优化算法整合到使用分子动力学(MD)仿真数据训练的机器学习(ML)模型中来实现的。在自下而上的方法中,使用深神经网络(DNN)优化了CG模型的粘结相互作用,在该神经网络(DNN)中,原子键分布匹配。原子分布模仿了局部链结构。在自上而下的方法中,通过再现依赖温度的实验密度来优化非键电势。我们证明,通过我们的机器学习启用的混合优化框架实现的CG模型参数可以满足与粗粒模型聚合物的经典方法相关的热力学一致性和可传递性问题。我们通过精确预测链尺寸以及链动力学(包括玻璃过渡温度的限制行为,扩散和应力松弛频谱,在潜在的参数化过程中都不包含我们的限制行为。预测性质的准确性是在分子理论和可用实验数据的背景下评估的。

This work presents a novel framework governing the development of an efficient, accurate, and transferable coarse-grained (CG) model of a polyether material. The proposed framework combines the two fundamentally different classical optimization approaches for the development of coarse-grained model parameters; namely bottom-up and top-down approaches. This is achieved through integrating the optimization algorithms into a machine learning (ML) model, trained using molecular dynamics (MD) simulation data. In the bottom-up approach, bonded interactions of the CG model are optimized using deep neural networks (DNN), where atomistic bonded distributions are matched. The atomistic distributions emulate the local chain structure. In the top-down approach, optimization of nonbonded potentials is accomplished by reproducing the temperature-dependent experimental density. We demonstrate that CG model parameters achieved through our machine-learning enabled hybrid optimization framework fulfills the thermodynamic consistency and transferability issues associated with the classical approaches to coarse-graining model polymers. We demonstrate the efficiency, accuracy, and transferability of the developed CG model, using our novel framework through accurate predictions of chain size as well as chain dynamics, including the limiting behavior of the glass transition temperature, diffusion, and stress relaxation spectrum, where none were included in the potential parameterization process. The accuracy of the predicted properties are evaluated in the context of molecular theories and available experimental data.

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