Grogan Francesca, Lei Huan, Li Xiantao, Baker Nathan A
Pacific Northwest National Laboratory, Richland, WA 99352, United States.
Department of Computational Mathematics, Science and Engineering, Michigan State University, East Lansing, MI 48824, United States.
J Comput Phys. 2020 Oct 1;418. doi: 10.1016/j.jcp.2020.109633. Epub 2020 Jun 3.
The complexity of molecular dynamics simulations necessitates dimension reduction and coarse-graining techniques to enable tractable computation. The generalized Langevin equation (GLE) describes coarse-grained dynamics in reduced dimensions. In spite of playing a crucial role in non-equilibrium dynamics, the memory kernel of the GLE is often ignored because it is difficult to characterize and expensive to solve. To address these issues, we construct a data-driven rational approximation to the GLE. Building upon previous work leveraging the GLE to simulate simple systems, we extend these results to more complex molecules, whose many degrees of freedom and complicated dynamics require approximation methods. We demonstrate the effectiveness of our approximation by testing it against exact methods and comparing observables such as autocorrelation and transition rates.
分子动力学模拟的复杂性需要降维和粗粒化技术来实现可处理的计算。广义朗之万方程(GLE)描述了降维后的粗粒化动力学。尽管GLE的记忆核在非平衡动力学中起着关键作用,但由于其难以表征且求解成本高昂,往往被忽视。为了解决这些问题,我们构建了一种数据驱动的GLE有理近似。基于先前利用GLE模拟简单系统的工作,我们将这些结果扩展到更复杂的分子,其众多的自由度和复杂的动力学需要近似方法。我们通过与精确方法进行对比测试,并比较自相关和跃迁速率等可观测量,来证明我们近似方法的有效性。