Li Hui, Li Wei, Li Shuhua, Ma Jing
School of Chemistry and Chemical Engineering, Institute of Theoretical and Computational Chemistry, Key Laboratory of Mesoscopic Chemistry of MOE, Nanjing University, Nanjing, P. R. China.
J Phys Chem B. 2008 Jun 12;112(23):7061-70. doi: 10.1021/jp800777e. Epub 2008 May 20.
Molecular fragmentation quantum mechanics (QM) calculations have been combined with molecular mechanics (MM) to construct the fragmentation QM/MM method for simulations of dilute solutions of macromolecules. We adopt the electrostatics embedding QM/MM model, where the low-cost generalized energy-based fragmentation calculations are employed for the QM part. Conformation energy calculations, geometry optimizations, and Born-Oppenheimer molecular dynamics simulations of poly(ethylene oxide), PEO(n) (n = 6-20), and polyethylene, PE(n) ( n = 9-30), in aqueous solution have been performed within the framework of both fragmentation and conventional QM/MM methods. The intermolecular hydrogen bonding and chain configurations obtained from the fragmentation QM/MM simulations are consistent with the conventional QM/MM method. The length dependence of chain conformations and dynamics of PEO and PE oligomers in aqueous solutions is also investigated through the fragmentation QM/MM molecular dynamics simulations.
分子碎片化量子力学（QM）计算已与分子力学（MM）相结合，构建了用于模拟大分子稀溶液的碎片化QM/MM方法。我们采用静电嵌入QM/MM模型，其中QM部分采用低成本的基于广义能量的碎片化计算。在碎片化和传统QM/MM方法的框架内，对聚环氧乙烷PEO(n)（n = 6 - 20）和聚乙烯PE(n)（n = 9 - 30）在水溶液中的构象能量计算、几何优化以及玻恩 - 奥本海默分子动力学模拟进行了研究。从碎片化QM/MM模拟中获得的分子间氢键和链构型与传统QM/MM方法一致。还通过碎片化QM/MM分子动力学模拟研究了PEO和PE低聚物在水溶液中链构象和动力学的长度依赖性。
