Bond breaking in epoxy systems: A combined QM/MM approach.
Bond breaking in epoxy systems: A combined QM/MM approach.
复制标题
环氧树脂体系中的断键：QM/MM 组合方法。
DOI：
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发表时间：
2016
影响因子：
4.4
通讯作者：
T. Breitzman
中科院分区：
文献类型：
--
作者：
S. Barr;G. Kedziora;A. M. Ecker;J. Moller;R. Berry;T. Breitzman
一种将量子力学（QM）和分子力学相结合的新方法已经被开发出来，可以准确有效地解释高应变下聚合物体系中的共价键断裂，而无需使用预定的断裂位置。使用这种方法将使人们更好地了解热固性材料断裂的机械化学起源。由于经典力场无法准确地解释键断裂，并且 QM 对模拟大型系统要求过高，因此需要采用混合方法。在此介绍的方法中，使用经典力场将应变施加到系统，并监控所有键长。当键拉伸超过阈值时，键周围的区域用于 QM 能量最小化，以确定哪些键断裂（如果有）。然后，QM 结果用于重构系统，以逐渐增大的应变继续经典模拟，直到触发另一个 QM 计算。通过这种方式，QM 计算仅在需要的时间和地点进行计算，从而实现高效的模拟。已经确定了用于能量最小化的鲁棒 QM 方法，以及 QM 区域大小和阈值键长的适当值。计算时间与经典分子力学模拟没有显着差异。
A novel method to combine quantum mechanics (QM) and molecular mechanics has been developed to accurately and efficiently account for covalent bond breaking in polymer systems under high strain without the use of predetermined break locations. Use of this method will provide a better fundamental understanding of the mechano-chemical origins of fracture in thermosets. Since classical force fields cannot accurately account for bond breaking, and QM is too demanding to simulate large systems, a hybrid approach is required. In the method presented here, strain is applied to the system using a classical force field, and all bond lengths are monitored. When a bond is stretched past a threshold value, a zone surrounding the bond is used in a QM energy minimization to determine which, if any, bonds break. The QM results are then used to reconstitute the system to continue the classical simulation at progressively larger strain until another QM calculation is triggered. In this way, a QM calculation is only computed when and where needed, allowing for efficient simulations. A robust QM method for energy minimization has been determined, as well as appropriate values for the QM zone size and the threshold bond length. Compute times do not differ dramatically from classical molecular mechanical simulations.
影响因子：
64.8
作者：
Kermode, J. R.;Albaret, T.;De Vita, A.
通讯作者：
De Vita, A.
影响因子：
15
作者：
Altun, A;Guallar, V;Thiel, W
通讯作者：
Thiel, W