Simulation of a single polymer chain in solution by combining lattice Boltzmann and molecular dynamics
Simulation of a single polymer chain in solution by combining lattice Boltzmann and molecular dynamics
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DOI：
10.1063/1.480156
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发表时间：
1999-11-01
影响因子：
4.4
通讯作者：
Dünweg, B
中科院分区：
文献类型：
--
作者：
Ahlrichs, P;Dünweg, B
在本文中，我们建立了一种新的有效的模拟聚合物-溶剂体系的方法，它结合了流体的格子Boltzmann方法和聚合物链的连续介质分子动力学(MD)模型。这两个部分由一个简单的耗散力耦合，而系统由添加到流体和聚合物上的随机力驱动。对新方法进行了广泛的测试，对溶剂中的单个聚合物链的情况进行了测试。验证了解析理论预测的动、静态标度特性。在此背景下，讨论了模拟盒的有限尺寸的影响。虽然有限尺寸修正标度通常为L-1(L表示盒子的线性尺寸)，但Rouse模的衰减率仅受L-3有限尺寸效应的影响。此外，映射到同一系统的现有MD仿真，使得新方法的所有物理输入值都可以从纯MD仿真中得到。因此，这两种方法可以进行定量比较，表明新方法允许更大的时间步长。两种方法的结果比较表明，由于静态链构象不完全匹配而导致系统偏差。(C)1999年美国物理研究所。[S0021-9606(99)50840-4]。
In this paper we establish a new efficient method for simulating polymer-solvent systems which combines a lattice Boltzmann approach for the fluid with a continuum molecular-dynamics (MD) model for the polymer chain. The two parts are coupled by a simple dissipative force while the system is driven by stochastic forces added to both the fluid and the polymer. Extensive tests of the new method for the case of a single polymer chain in a solvent are performed. The dynamic and static scaling properties predicted by analytical theory are validated. In this context, the influence of the finite size of the simulation box is discussed. While usually the finite size corrections scale as L-1 (L denoting the linear dimension of the box), the decay rate of the Rouse modes is only subject to an L-3 finite size effect. Furthermore, the mapping to an existing MD simulation of the same system is done so that all physical input values for the new method can be derived from pure MD simulation. Both methods can thus be compared quantitatively, showing that the new method allows for much larger time steps. Comparison of the results for both methods indicates systematic deviations due to nonperfect match of the static chain conformations. (C) 1999 American Institute of Physics. [S0021-9606(99)50840-4].