Phase Equilibria Modeling with Systematically Coarse-Grained Models-A Comparative Study on State Point Transferability.
Phase Equilibria Modeling with Systematically Coarse-Grained Models-A Comparative Study on State Point Transferability.
复制标题
系统粗粒度模型的相平衡建模——状态点可转移性的比较研究。
DOI：
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发表时间：
2019
影响因子：
3.3
通讯作者：
N. V. D. van der Vegt
中科院分区：
文献类型：
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作者：
Gregor Deichmann;M. Dallavalle;D. Rosenberger;N. V. D. van der Vegt
软物质系统的粗粒度(CG)模型可以使用各种方法进行参数化。在系统的粗粒化过程中，使用参考细粒度模拟来计算有效的相互作用。参考系的热力学和结构性质在多大程度上被重现，关键取决于用于对模型进行参数化的粗粒化方法。本文对不同的CG模型模拟正己烷和全氟正己烷体系汽液平衡热力学的能力进行了比较研究。CG模型采用粗粒化方法，基于(A)结构和(B)耦合自由能的再现。尽管基于结构的模型显示出对压力的高估，因此在再现汽液热力学方面表现得相对较差，但基于耦合自由能的方法，特别是条件可逆功方法，能够更好地再现联合原子参考模拟的汽液相图，同时几乎与基于结构的CG模型一样准确地再现液体结构。这说明了使用这些方法计算的相互作用势的状态点可迁移性，因为所得到的CG模型(已在300K被参数化)能够准确地模拟直到临界点的热力学性质。
Coarse-grained (CG) models for soft matter systems can be parameterized using a variety of approaches. In systematic coarse-graining procedures, effective interactions are calculated using a reference fine-grained simulation. The degree to which thermodynamical and structural properties of the reference system are reproduced depends critically on the coarse-graining method used to parameterize the model. In this article, a comparative study is presented on the capability of different CG models to reproduce vapor-liquid equilibrium thermodynamics of hexane and perfluorohexane systems. CG models are developed using coarse-graining methods based on the reproduction of (a) structure and (b) coupling free energies. Although the structure-based models show an overestimation of the pressure and therefore perform relatively poorly in reproducing the vapor-liquid thermodynamics, it is shown that methods based on coupling free energies, in particular the conditional reversible work method, are capable of better reproducing the vapor-liquid phase diagram of the united-atom reference simulations, while reproducing the liquid structure almost as accurately as the structure-based CG model. This illustrates the state point transferability of the interaction potentials calculated using these methods, as the resulting CG model (which has been parameterized at 300 K) is capable of accurately modeling the thermodynamic properties up to the critical point.