General Force-Field Parametrization Scheme for Molecular Dynamics Simulations of Conjugated Materials in Solution.
General Force-Field Parametrization Scheme for Molecular Dynamics Simulations of Conjugated Materials in Solution.
复制标题
DOI：
10.1021/acs.jctc.5b01195
复制
发表时间：
2016-08-09
影响因子：
5.5
通讯作者：
Galbraith I
中科院分区：
文献类型：
--
作者：
Wildman J;Repiščák P;Paterson MJ;Galbraith I
我们描述了一种获得共轭聚合物经典分子动力学模拟的力场参数的一般方案。我们确定了一种计算成本低廉的方法来计算准确的单体间二面体电位和部分电荷。我们的研究结果表明，使用两步几何优化方法和使用DFT方法的单点能量计算产生的势能比高级理论计算更有利。我们还报道了改变共轭主链长度和烷基侧链长度对二面体轮廓和部分电荷分布的影响，并确定了收敛长度的存在性，在此收敛长度之上，在力场参数集中实现了收敛。因此，我们确定哪些计算需要精确的参数化，以及给定分子变化的给定参数集的范围。我们对二辛基芴和己基噻吩的长低聚物在显式溶剂中进行了模拟，发现持久性长度和端长分布与实验值一致。
We describe a general scheme to obtain force-field parameters for classical molecular dynamics simulations of conjugated polymers. We identify a computationally inexpensive methodology for calculation of accurate intermonomer dihedral potentials and partial charges. Our findings indicate that the use of a two-step methodology of geometry optimization and single-point energy calculations using DFT methods produces potentials which compare favorably to high level theory calculation. We also report the effects of varying the conjugated backbone length and alkyl side-chain lengths on the dihedral profiles and partial charge distributions and determine the existence of converged lengths above which convergence is achieved in the force-field parameter sets. We thus determine which calculations are required for accurate parametrization and the scope of a given parameter set for variations to a given molecule. We perform simulations of long oligomers of dioctylfluorene and hexylthiophene in explicit solvent and find peristence lengths and end-length distributions consistent with experimental values.