Electronic coarse graining enhances the predictive power of molecular simulation allowing challenges in water physics to be addressed
Electronic coarse graining enhances the predictive power of molecular simulation allowing challenges in water physics to be addressed
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DOI：
10.1016/j.jcp.2016.08.030
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发表时间：
2016-12-01
影响因子：
4.1
通讯作者：
Martyna, Glenn J.
中科院分区：
文献类型：
--
作者：
Cipcigan, Flaviu S.;Sokhan, Vlad P.;Martyna, Glenn J.
限制分子动力学模拟预测能力的一个关键因素是输入力场的准确性和可转移性。力场受到异质环境的挑战，在异质环境中，电子响应引起生物学上重要的力，如多体极化和分散。正如Cochran在1959年所描述的，凝聚相中极化的重要性很早就被认识到[Philosophical杂志4（1959）1082-1086] [32]。目前在分子模拟中，色散力在两体水平和偶极极限下处理，尽管在凝聚相中三体项的重要性由Barker在20世纪80年代[Phys. Rev. Lett. 57（1986）230-233] [72]。在同等基础上处理偏振和色散的一种方法是将分子部分周围的电子粗粒化为单个量子谐振子（参见图1）。Hirschfelder，Curtiss and Bird 1954 [The Molecular Theory of Gases and Liquids（1954）].该方法，当解决强耦合超出偶极极限，给出了一个描述的长程力，包括两个和多个机构的条款，所有订单。在过去的十年中，实现强耦合极限所需的工具已经开发出来，最终形成了一个可转移的水模型，在整个相图中具有出色的预测能力。可移植性的出现是因为环境自动识别重要的远程交互，而不是建模者通过一组有限的表达式。在这里，我们讨论了预测多尺度材料建模中的电子粗粒化的作用，并描述了该方法在通用分子动力学软件QDO_MD中的第一个实现。(C)2016 Elsevier Inc. All rights reserved.
One key factor that limits the predictive power of molecular dynamics simulations is the accuracy and transferability of the input force field. Force fields are challenged by heterogeneous environments, where electronic responses give rise to biologically important forces such as many-body polarisation and dispersion. The importance of polarisation in the condensed phase was recognised early on, as described by Cochran in 1959 [Philosophical Magazine 4 (1959) 1082-1086] [32]. Currently in molecular simulation, dispersion forces are treated at the two-body level and in the dipole limit, although the importance of three-body terms in the condensed phase was demonstrated by Barker in the 1980s [Phys. Rev. Lett. 57 (1986) 230-233] [72]. One approach for treating both polarisation and dispersion on an equal basis is to coarse grain the electrons surrounding a molecular moiety to a single quantum harmonic oscillator (cf. Hirschfelder, Curtiss and Bird 1954 [The Molecular Theory of Gases and Liquids (1954)] [37]). The approach, when solved in strong coupling beyond the dipole limit, gives a description of long-range forces that includes two-and many-body terms to all orders. In the last decade, the tools necessary to implement the strong coupling limit have been developed, culminating in a transferable model of water with excellent predictive power across the phase diagram. Transferability arises since the environment automatically identifies the important long range interactions, rather than the modeller through a limited set of expressions. Here, we discuss the role of electronic coarse-graining in predictive multiscale materials modelling and describe the first implementation of the method in a general purpose molecular dynamics software: QDO_MD. (C) 2016 Elsevier Inc. All rights reserved.