Electronically coarse-grained molecular dynamics using quantum Drude oscillators
Electronically coarse-grained molecular dynamics using quantum Drude oscillators
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DOI：
10.1080/00268976.2013.843032
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发表时间：
2013-12-01
影响因子：
1.7
通讯作者：
Martyna, G. J.
中科院分区：
文献类型：
--
作者：
Jones, A. P.;Crain, J.;Martyna, G. J.
标准的分子动力学（MD）模拟通常利用分子间力的基本描述，其由固定的、成对的、原子中心的库仑、货车德瓦尔斯和短程排斥项组成。重要的相互作用，如多体极化和多体色散，这是敏感的环境变化通常被忽略，其影响有效地处理内的平均场近似再现一个单一的热力学状态点或物理环境。这导致对当今感兴趣的复杂界面进行建模时遇到困难，其中行为可能与参数化机制截然不同。在这里，我们描述了高斯粗粒度的电子结构，自然产生多体极化和色散相互作用的建设和属性。电子结构产生于一组分布式量子德鲁德振荡器（QDO）的完全量子力学处理，谐波原子通过静电（库仑）相互作用相互作用和其他部分;这种粗粒度的方法能够描述多体极化和色散，但不能描述必须参数化的短程相互作用。我们描述了如何在飞行中的力量，由于这种交换自由高斯模型可能会产生与线性尺度的系统中的原子数使用绝热路径积分分子动力学量子德鲁德振荡器技术（APIMD-QDO）。我们通过对水的液-气界面的研究，证明了QDO方法对现实系统的适用性。
Standard molecular dynamics (MD) simulations generally make use of a basic description of intermolecular forces which consists of fixed, pairwise, atom-centred Coulomb, van der Waals and short-range repulsive terms. Important interactions such as many-body polarisation and many-body dispersion which are sensitive to changes in the environment are usually neglected, and their effects treated effectively within mean-field approximations to reproduce a single thermodynamic state point or physical environment. This leads to difficulties in modelling the complex interfaces of interest today where the behaviour may be quite different from the regime of parameterisation. Here, we describe the construction and properties of a Gaussian coarse-grained electronic structure, which naturally generates many-body polarisation and dispersion interactions. The electronic structure arises from a fully quantum mechanical treatment of a set of distributed quantum Drude oscillators (QDOs), harmonic atoms which interact with each other and other moieties via electrostatic (Coulomb) interactions; this coarse-grained approach is capable of describing many-body polarisation and dispersion but not short-range interactions which must be parametrised. We describe how on-the-fly forces due to this exchange-free Gaussian model may be generated with linear scale in the number of atoms in the system using an adiabatic path integral molecular dynamics for quantum Drude oscillators technique (APIMD-QDO). We demonstrate the applicability of the QDO approach to realistic systems via a study of the liquid-vapour interface of water.