TINKTEP: A fully self-consistent, mutually polarizable QM/MM approach based on the AMOEBA force field
TINKTEP: A fully self-consistent, mutually polarizable QM/MM approach based on the AMOEBA force field
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DOI：
10.1063/1.4962909
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发表时间：
2016-09-28
影响因子：
4.4
通讯作者：
Skylaris, Chris-Kriton
中科院分区：
文献类型：
--
作者：
Dziedzic, Jacek;Mao, Yuezhi;Skylaris, Chris-Kriton
我们提出了一种新的量子力学/分子力学（QM/MM）方法，其中量子子系统耦合到由AMOEBA极化力场描述的经典子系统。我们的方法允许QM和MM子系统之间的相互极化，通过多极静电的影响。通过总能量最小化方案，QM和MM子系统都实现了自洽性。我们提供了一个表达式的耦合QM/MM系统的哈密顿量，我们使用梯度法最小化。QM子系统由ONETEP线性尺度DFT方法描述，该方法使用表示在一组等效于平面波的周期sinc基函数中的严格局部化轨道。MM子系统由多极可极化力场AMOEBA描述，如TINKER中所实现的。分布式多极子分析是用来获得，在飞行中，一个经典的代表性的QM子系统的原子为中心的多极。这种辅助表示用于QM和MM之间的所有极化相互作用，使我们能够像AMOEBA一样对待它们。我们验证了我们的方法在测试中的溶质-溶剂相互作用能，中性和带电分子，展示了量子和经典的自由度的同时优化。令人鼓舞的是，我们发现，列入明确的偏振在MM的QM/MM部分提高了与完全QM计算的协议。由AIP出版社出版。
We present a novel quantum mechanical/molecular mechanics (QM/MM) approach in which a quantum subsystem is coupled to a classical subsystem described by the AMOEBA polarizable force field. Our approach permits mutual polarization between the QM and MM subsystems, effected through multipolar electrostatics. Self-consistency is achieved for both the QM and MM subsystems through a total energy minimization scheme. We provide an expression for the Hamiltonian of the coupled QM/MM system, which we minimize using gradient methods. The QM subsystem is described by the ONETEP linear-scaling DFT approach, which makes use of strictly localized orbitals expressed in a set of periodic sinc basis functions equivalent to plane waves. The MM subsystem is described by the multipolar, polarizable force field AMOEBA, as implemented in TINKER. Distributed multipole analysis is used to obtain, on the fly, a classical representation of the QM subsystem in terms of atom-centered multipoles. This auxiliary representation is used for all polarization interactions between QM and MM, allowing us to treat them on the same footing as in AMOEBA. We validate our method in tests of solute-solvent interaction energies, for neutral and charged molecules, demonstrating the simultaneous optimization of the quantum and classical degrees of freedom. Encouragingly, we find that the inclusion of explicit polarization in the MM part of QM/MM improves the agreement with fully QM calculations. Published by AIP Publishing.