一种用于过渡态界面采样和正向通量采样模拟中扩散过程的自由能重构的有效方法。

An efficient method to reconstruct free energy profiles for diffusive processes in transition interface sampling and forward flux sampling simulations.

机构信息

Institute of Materials Science and Technology, TU Wien, Vienna, Austria.

Faculty of Physics, University of Vienna, Vienna, Austria.

出版信息

J Chem Phys. 2019 Mar 7;150(9):094114. doi: 10.1063/1.5080933.

DOI:10.1063/1.5080933

PMID:30849894

Abstract

We propose a Reweighted Partial Path (RPP) method to compute free energy profiles for diffusive processes in single Transition Interface Sampling (TIS) or Forward Flux Sampling (FFS) simulations. The method employs a partial path reweighting strategy, based on the memory loss assumption for diffusive systems, to derive the equilibrium distribution of states along a chosen order parameter from TIS or FFS trajectories. No additional calculations such as reverse TIS or umbrella sampling are required. The application of the RPP method is demonstrated by calculating the nucleation free energy of early-stage Cu precipitates in a dilute Fe-Cu alloy.

摘要

我们提出了一种重加权部分路径（RPP）方法，用于计算单转换界面采样（TIS）或正向通量采样（FFS）模拟中扩散过程的自由能分布。该方法采用基于扩散系统记忆损失假设的部分路径重加权策略，从 TIS 或 FFS 轨迹中推导出选定序参量沿给定方向的状态平衡分布。不需要进行其他计算，如反向 TIS 或伞状采样。RPP 方法的应用通过计算稀 Fe-Cu 合金中早期 Cu 析出物的成核自由能来演示。