Multiscale coarse graining of liquid-state systems
Multiscale coarse graining of liquid-state systems
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DOI：
10.1063/1.2038787
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发表时间：
2005-10-01
影响因子：
4.4
通讯作者：
Voth, GA
中科院分区：
文献类型：
--
作者：
Izvekov, S;Voth, GA
描述了一种方法来系统地推导粗粒（CG）力场的分子液体从基本的原子尺度的力量。颗粒间力场的粗粒化是通过对从目标系统CG位点的原子轨迹和力数据获得的轨迹和力应用力匹配方法来实现的。CG站点可以与原子团的质心相关联，因为从原子数据评估作用在这些站点上的力是简单的。由此产生的系统被称为多尺度粗粒度（MS-CG）表示。液体的MS-CG方法在此适用于水和甲醇。对于这两种液体的一个网站和两个网站的CG表示没有显式处理的长程静电已导出。此外，对于水的两个站点模型具有显式的远程静电已被开发。为了改善热力学性质（例如，压力和密度）的MS-CG模型，瞬时维里的约束被纳入力匹配程序。所得到的模型的性能进行了评估，对底层的原子模拟和实验。与现有的液体系统粗粒化方法相比，MS-CG方法是通用的，仅依赖于参考原子系统中的原子间相互作用。(c)2005年美国物理学会。
A methodology is described to systematically derive coarse-grained (CG) force fields for molecular liquids from the underlying atomistic-scale forces. The coarse graining of an interparticle force field is accomplished by the application of a force-matching method to the trajectories and forces obtained from the atomistic trajectory and force data for the CG sites of the targeted system. The CG sites can be associated with the centers of mass of atomic groups because of the simplicity in the evaluation of forces acting on these sites from the atomistic data. The resulting system is called a multiscale coarse-grained (MS-CG) representation. The MS-CG method for liquids is applied here to water and methanol. For both liquids one-site and two-site CG representations without an explicit treatment of the long-ranged electrostatics have been derived. In addition, for water a two-site model having the explicit long-ranged electrostatics has been developed. To improve the thermodynamic properties (e.g., pressure and density) for the MS-CG models, the constraint for the instantaneous virial was included into the force-match procedure. The performance of the resulting models was evaluated against the underlying atomistic simulations and experiment. In contrast with existing approaches for coarse graining of liquid systems, the MS-CG approach is general, relies only on the interatomic interactions in the reference atomistic system. (c) 2005 American Institute of Physics.