Albaugh Alex, Head-Gordon Teresa
Departments of Chemical & Biomolecular Engineering, ‡Chemistry, and §Bioengineering, ∥Chemical Sciences Division, Lawrence Berkeley National Laboratory, University of California , Berkeley, California 94720, United States.
J Chem Theory Comput. 2017 Nov 14;13(11):5207-5216. doi: 10.1021/acs.jctc.7b00838. Epub 2017 Oct 16.
With polarization becoming an increasingly common feature in classical molecular simulation, it is important to develop methods that can efficiently and accurately evaluate the many-body polarization solution. In this work, we expand the theoretical framework of our inertial extended Langrangian, self-consistent field iteration-free method (iEL/0-SCF), introduced for point induced dipoles, to the polarization model of a Drude oscillator. When applied to the polarizable simple point charge model (PSPC) for water, our iEL/0-SCF method for Drude polarization is as stable as a well-converged SCF solution and more stable than traditional extended Lagrangian (EL) approaches or EL formulations based on two temperature ensembles where Drude particles are kept "colder" than the real degrees of freedom. We show that the iEL/0-SCF method eliminates the need for mass repartitioning from parent atoms onto Drude particles, obeys system conservation of linear and angular momentum, and permits the extension of the integration time step of a basic molecular dynamics simulation to 6.0 fs for PSPC water.
随着极化在经典分子模拟中变得越来越普遍，开发能够高效准确地评估多体极化解的方法变得很重要。在这项工作中，我们将我们为点感应偶极子引入的惯性扩展拉格朗日自洽场无迭代方法（iEL/0-SCF）的理论框架扩展到德鲁德振子的极化模型。当应用于水的可极化简单点电荷模型（PSPC）时，我们的德鲁德极化iEL/0-SCF方法与收敛良好的SCF解一样稳定，并且比传统的扩展拉格朗日（EL）方法或基于双温度系综的EL公式更稳定，在双温度系综中，德鲁德粒子比实际自由度“更冷”。我们表明，iEL/0-SCF方法无需从母体原子到德鲁德粒子的质量重新分配，遵守系统的线性和角动量守恒，并允许将基本分子动力学模拟的积分时间步长扩展到PSPC水的6.0飞秒。
