Pairwise adaptive thermostats for improved accuracy and stability in dissipative particle dynamics
Pairwise adaptive thermostats for improved accuracy and stability in dissipative particle dynamics
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DOI：
10.1016/j.jcp.2016.07.034
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发表时间：
2016-07
期刊：
影响因子：
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通讯作者：
B. Leimkuhler;Xiaocheng Shang
中科院分区：
文献类型：
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作者：
B. Leimkuhler;Xiaocheng Shang
我们研究了耗散粒子动力学（DPD）和动量守恒分子动力学的制定和数值处理。我们表明，通过采用精确匹配DPD模拟动态特性的成对自适应Langevin恒温器，可以提高DPD的准确性和稳定性（例如，自相关函数），同时使用负反馈回路自动校正热力学平均值。在低摩擦制度，它是可能的，以取代DPD的一个更简单的动量守恒的变体的Nosé-胡佛-朗之万方法的基础上恒温只成对的相互作用，我们表明，这种方法有一个额外的顺序的精度为一类重要的可观的（超收敛结果），同时也允许更大的时间步长比替代品。文章中提到的所有方法都很容易实现。数值实验进行平衡和非平衡设置，使用Lees-Edwards边界条件诱导剪切流。
We examine the formulation and numerical treatment of dissipative particle dynamics (DPD) and momentum-conserving molecular dynamics. We show that it is possible to improve both the accuracy and the stability of DPD by employing a pairwise adaptive Langevin thermostat that precisely matches the dynamical characteristics of DPD simulations (e.g., autocorrelation functions) while automatically correcting thermodynamic averages using a negative feedback loop. In the low friction regime, it is possible to replace DPD by a simpler momentum-conserving variant of the Nosé–Hoover–Langevin method based on thermostatting only pairwise interactions; we show that this method has an extra order of accuracy for an important class of observables (a superconvergence result), while also allowing larger timesteps than alternatives. All the methods mentioned in the article are easily implemented. Numerical experiments are performed in both equilibrium and nonequilibrium settings; using Lees–Edwards boundary conditions to induce shear flow.