A variational approach to assess reaction coordinates for two-step crystallization.
A variational approach to assess reaction coordinates for two-step crystallization.
复制标题
评估两步结晶反应坐标的变分方法。
DOI：
--
复制
发表时间：
2022
影响因子：
4.4
通讯作者：
M. Salvalaglio
中科院分区：
文献类型：
--
作者：
Aaron R. Finney;M. Salvalaglio
基于分子和粒子的模拟提供了在微观细节上测试经典成核理论有效性的工具。在这项工作中，确定相分离的成核机制和速率需要一个适当定义的反应坐标来描述非平衡母相的转变，模拟器可以提供无数选项。在本文中，我们描述了马尔可夫过程变分方法的应用，以量化反应坐标对过饱和胶体悬浮液结晶研究的适用性。我们的分析表明，与凝聚相中的粒子数、系统势能和近似构型熵相关的集体变量（CVs）通常是定量描述结晶过程的最合适的有序参数。我们应用时滞独立分量分析来减少由这些cv构建的高维反应坐标来构建马尔可夫状态模型（msm），该模型表明在模拟环境中，两个屏障将过饱和流体相与晶体分离。无论所采用的序参数空间的维数如何，均质谱提供了一致的晶体成核率估计；然而，两步机制只有在更高维度的msm光谱聚类中才一致地明显。由于该方法具有通用性和可移植性，我们采用的变分方法可以为研究晶体成核的控制提供一个有用的框架。
Molecule- and particle-based simulations provide the tools to test, in microscopic detail, the validity of classical nucleation theory. In this endeavor, determining nucleation mechanisms and rates for phase separation requires an appropriately defined reaction coordinate to describe the transformation of an out-of-equilibrium parent phase for which myriad options are available to the simulator. In this article, we describe the application of the variational approach to Markov processes to quantify the suitability of reaction coordinates to study crystallization from supersaturated colloid suspensions. Our analysis indicates that collective variables (CVs) that correlate with the number of particles in the condensed phase, the system potential energy, and approximate configurational entropy often feature as the most appropriate order parameters to quantitatively describe the crystallization process. We apply time-lagged independent component analysis to reduce high-dimensional reaction coordinates constructed from these CVs to build Markov State Models (MSMs), which indicate that two barriers separate a supersaturated fluid phase from crystals in the simulated environment. The MSMs provide consistent estimates for crystal nucleation rates, regardless of the dimensionality of the order parameter space adopted; however, the two-step mechanism is only consistently evident from spectral clustering of the MSMs in higher dimensions. As the method is general and easily transferable, the variational approach we adopt could provide a useful framework to study controls for crystal nucleation.
影响因子：
4.4
作者：
Blow, Katarina E.;Quigley, David;Sosso, Gabriele C.
通讯作者：
Sosso, Gabriele C.
影响因子：
4.4
作者：
Prinz, Jan-Hendrik;Wu, Hao;Noe, Frank
通讯作者：
Noe, Frank
DOI：
10.1073/pnas.2008561117
发表时间：
2020-11-10
影响因子：
11.1
作者：
Fang H;Hagan MF;Rogers WB
通讯作者：
Rogers WB