Chemically transferable coarse-grained potentials from conditional reversible work calculations
Chemically transferable coarse-grained potentials from conditional reversible work calculations
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DOI：
10.1063/1.4758936
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发表时间：
2012-10-21
影响因子：
4.4
通讯作者：
van der Vegt, N. F. A.
中科院分区：
文献类型：
--
作者：
Brini, E.;van der Vegt, N. F. A.
在软物质系统的多尺度模拟中，有效对势的可表示性和可传递性还没有得到很好的理解。在本文中，我们研究了液态系统组成的正构烷烃，粗粒（CG）的潜力，可以假定成对添加剂，并已获得使用条件可逆功（CRW）方法。CRW方法是一种基于自由能的粗粒化方法，它通过在对水平上进行粗粒化，严格地提供了一个描述嵌入其各自化学环境中的两个映射原子团（珠）之间相互作用自由能的对势。相互作用的成对性质及其对化学键合环境的依赖性使得CRW势非常适合化学可转移性的研究。我们报告CRW潜力己烷使用映射方案，合并两个重原子在一个CG珠。结果表明，该模型是化学和pherically转移到不同链长的烷烃在液相中的熔点和沸点之间的温度下，在大气压（1个大气压）的压力条件下。它进一步表明，CRW-CG势可以很容易地获得从一个单一的模拟的液体状态使用的自由能微扰方法，从而提供了一个快速和通用的分子粗粒化方法的脂肪族分子。(C)2012年美国物理学会。[http：//dx.doi.org/10.1063/1.4758936]
The representability and transferability of effective pair potentials used in multiscale simulations of soft matter systems is ill understood. In this paper, we study liquid state systems composed of n-alkanes, the coarse-grained (CG) potential of which may be assumed pairwise additive and has been obtained using the conditional reversible work (CRW) method. The CRW method is a free-energy-based coarse-graining procedure, which, by means of performing the coarse graining at pair level, rigorously provides a pair potential that describes the interaction free energy between two mapped atom groups (beads) embedded in their respective chemical environments. The pairwise nature of the interactions combined with their dependence on the chemically bonded environment makes CRW potentials ideally suited in studies of chemical transferability. We report CRW potentials for hexane using a mapping scheme that merges two heavy atoms in one CG bead. It is shown that the model is chemically and thermodynamically transferable to alkanes of different chain lengths in the liquid phase at temperatures between the melting and the boiling point under atmospheric (1 atm) pressure conditions. It is further shown that CRW-CG potentials may be readily obtained from a single simulation of the liquid state using the free energy perturbation method, thereby providing a fast and versatile molecular coarse graining method for aliphatic molecules. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4758936]