Combined coarse-grained and atomistic simulation of liquid bisphenol A-polycarbonate: Liquid packing and intramolecular structure
Combined coarse-grained and atomistic simulation of liquid bisphenol A-polycarbonate: Liquid packing and intramolecular structure
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DOI：
10.1021/ma0213495
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发表时间：
2003-01-14
期刊：
影响因子：
5.5
通讯作者：
Kremer, K
中科院分区：
文献类型：
--
作者：
Abrams, CF;Kremer, K
我们提出了一个新的粗粒度的计划，有效的分子动力学模拟聚碳酸酯液体和比较其有效性，以前提出的模型，使用不同的粗粒度表示。更现实地占排除体积的亚苯基共聚单体单元在粗粒度的模拟的效果进行检查。新的处理避免了工件所产生的球形包装，其中占主导地位的液体结构和动力学在旧的计划，导致显着改善的平衡时间，系统运行在典型的处理温度为570 K。然而，我们只观察到一个轻微的改善（10（-4）eV/原子），在平衡的原子详细的样品，从平衡的粗粒度配置逆映射。在原子分辨骨干键和扭转角的分布是相同的，使用这两个计划，作为计算液体相干散射函数。这表明，在粗化水平存在的文物被有效地擦除的平衡，在全面的原子分辨率，至少对于系统具有相对较短的链远高于玻璃化转变温度。
We present a new coarse-graining scheme for efficient molecular dynamics simulations of polycarbonate liquids and compare its effectiveness to that of a previously presented model which uses a different coarse-grained representation. The effect of more realistically accounting for the excluded volume of the phenylene comonomeric units in the coarse-grained simulation is examined. The new treatment avoids artifacts arising from sphere-packing, which dominate the liquid structure and dynamics in the older scheme, leading to a significant improvement in the equilibration time, for systems run at the typical processing temperature of 570 K. However, we observe only a slight improvement (10(-4) eV/atom) in the equilibration of atomistically detailed samples that are inverse-mapped from the equilibrated coarse-grained configurations. Distributions in the atomistically resolved backbone bond and torsion angles are identical using the two schemes, as are computed liquid coherent scattering functions. This indicates that artifacts present at the coarsened level are effectively erased by equilibration at full-blown atomistic resolution, at least for systems with relatively short chains well above the glass transition temperature.