论文标题
基于密度功能理论的量子力学/粗粒分子力学：理论和实施
Density Functional Theory-based Quantum Mechanics/Coarse-grained Molecular Mechanics: Theory and Implementation
论文作者
论文摘要
量子力学/分子力学（QM/mm）是一种标准计算工具，用于描述具有多个自由度的系统（包括聚合物，酶和复杂溶剂中的反应分子）的化学反应性。但是，由于相关的长松弛时间，QM能量评估的高计算成本以及昂贵的远距离静电学，QM/MM不太适合具有复杂MM动力学的系统。最近，提出了MM部分的系统粗粒度，以克服这些QM/MM限制，以量子力学/粗粒分子力学（QM/CG-MM）方法的形式。在此，我们在密度功能理论形式主义中重新铸造QM/CG-MM，并通过采用力匹配的变分原理来访问两个模型系统的方法性能：MM CCL4液体中的QM CCL4以及TERT叔丁基二氯酸盐在MM CCL4溶解体中与苯唑激光的反应。我们发现DFT-QM/CG-MM准确地重现了QM和CG-MM子系统之间的DFT-QM/MM径向分布函数以及3体相关性。反应的自由能谱也很好地描述了，误差<1-2 kcal/mol。 DFT-QM/CG-MM是一种一般，系统和计算有效的方法，可在粗粒分子模型中包括化学反应性。
Quantum mechanics/molecular mechanics (QM/MM) is a standard computational tool for describing chemical reactivity in systems with many degrees of freedom, including polymers, enzymes, and reacting molecules in complex solvents. However, QM/MM is less suitable for systems with complex MM dynamics due to associated long relaxation times, the high computational cost of QM energy evaluations, and expensive long-range electrostatics. Recently, a systematic coarse-graining of the MM part was proposed to overcome these QM/MM limitations in the form of the quantum mechanics/coarse-grained molecular mechanics (QM/CG-MM) approach. Herein, we recast QM/CG-MM in the density functional theory formalism and, by employing the force-matching variational principle, access the method performance for two model systems: QM CCl4 in the MM CCl4 liquid and the reaction of tert-butyl hypochlorite with the benzyl radical in the MM CCl4 solvent. We find that DFT-QM/CG-MM accurately reproduces DFT-QM/MM radial distribution functions and 3-body correlations between QM and CG-MM subsystems. The free energy profile of the reaction is also described well, with an error < 1-2 kcal/mol. DFT-QM/CG-MM is a general, systematic, and computationally efficient approach to include chemical reactivity in coarse-grained molecular models.
