A Gentle Stochastic Thermostat for Molecular Dynamics
A Gentle Stochastic Thermostat for Molecular Dynamics
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DOI：
10.1007/s10955-009-9734-0
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发表时间：
2009-04-01
影响因子：
1.6
通讯作者：
Theil, Florian
中科院分区：
文献类型：
--
作者：
Leimkuhler, Ben;Noorizadeh, Emad;Theil, Florian
本文讨论了分子动力学中正则测度采样的一种动力学方法。我们提出了一种方法，推广了最近提出的方案（Samoletov等人，J. Stat. 128：1321-1336，2007），并且其通过使用与Nos，dynamics的装置类似的装置来控制温度，但是添加随机噪声以提高遍历性。与朗之万动力学不同，在朗之万动力学中，噪声直接添加到每个物理自由度，新方案依赖于与单个布朗粒子的间接耦合。对于一个具有调和势的模型，我们证明了在一个温和的非共振假设下，我们可以恢复正则分布。尽管它的随机性，实验表明，它引入了一个相对较弱的扰动效应的物理动力学，测量的时间自相关函数的扰动。即使在模拟的早期阶段，动能也得到了很好的控制。
We discuss a dynamical technique for sampling the canonical measure in molecular dynamics. We present a method that generalizes a recently proposed scheme (Samoletov et al., J. Stat. Phys. 128:1321-1336, 2007), and which controls temperature by use of a device similar to that of Nos, dynamics, but adds random noise to improve ergodicity. In contrast to Langevin dynamics, where noise is added directly to each physical degree of freedom, the new scheme relies on an indirect coupling to a single Brownian particle. For a model with harmonic potentials, we show under a mild non-resonance assumption that we can recover the canonical distribution. In spite of its stochastic nature, experiments suggest that it introduces a relatively weak perturbative effect on the physical dynamics, as measured by perturbation of temporal autocorrelation functions. The kinetic energy is well controlled even in the early stages of a simulation.