Effective control of the transport coefficients of a coarse-grained liquid and polymer models using the dissipative particle dynamics and Lowe-Andersen equations of motion.
Effective control of the transport coefficients of a coarse-grained liquid and polymer models using the dissipative particle dynamics and Lowe-Andersen equations of motion.
复制标题
DOI：
10.1039/b817584e
复制
发表时间：
2009-03
期刊：
影响因子：
--
通讯作者：
H. Qian;C. Liew;F. Müller-Plathe
中科院分区：
文献类型：
--
作者：
H. Qian;C. Liew;F. Müller-Plathe
通过迭代玻尔兹曼反演获得的粗粒度模型的动力学[J].计算。 Chem., 2003, 24, 1624] 总是比父原子模型更快。在这项工作中，耗散粒子动力学 (DPD) 和 Lowe-Andersen (LA) 运动方程应用于粗粒度模拟中，以减慢粗粒度动力学速度。两种方法都提供有效摩擦，并且都保持局部线性动量，因此可以用于粘度的计算。研究了液体乙苯和短链聚苯乙烯熔体的粗粒模型。基于四种不同温度下乙苯的模拟，提出了选择 DPD 中的噪声强度或 LA 动力学中的浴碰撞频率的经验规则，以再现完全原子模拟的扩散系数。使用乙苯系统开发的规则最终在聚苯乙烯熔体上进行测试，从而实现了实验扩散系数的接近再现。
The dynamics of coarse-grained models obtained through iterative Boltzmann inversion [J. Comput. Chem., 2003, 24, 1624] is always faster than that of the parent atomistic models. In this work, the dissipative particle dynamics (DPD) and Lowe-Andersen (LA) equations of motion are applied in coarse-grained simulations to slow down the coarse-grained dynamics. Both methods provide effective friction and both conserve the linear momentum locally, so that they can be used for the calculation of viscosities. Coarse-grained models of liquid ethylbenzene and of short-chain polystyrene melts are studied. Based on the simulation of ethylbenzene at four different temperatures, empirical rules are proposed for choosing the noise strength in DPD or the bath collision frequency in LA dynamics to reproduce the diffusion coefficients of the fully atomistic simulation. The rules developed using the ethylbenzene system are finally tested on the polystyrene melt where they lead to a close reproduction of the experimental diffusion coefficient.