Effect of correlation on viscosity and diffusion in molecular-dynamics simulations
Effect of correlation on viscosity and diffusion in molecular-dynamics simulations
复制标题
DOI：
10.1103/physreve.90.043101
复制
发表时间：
2014-10-06
影响因子：
2.4
通讯作者：
Ticknor, Christopher
中科院分区：
文献类型：
--
作者：
Meyer, Edmund R.;Kress, Joel D.;Ticknor, Christopher
在温密物质（WDM）体系中，扩散和粘度等材料性质可以从冗长的量子分子动力学模拟中获得，其中电子的量子行为使用Kohn-Sham或无轨道密度泛函理论表示。为了减少模拟持续时间，我们拟合自相关函数（ACF）的时间依赖性，然后使用拟合来找到扩散和粘度的值。该拟合过程避免了ACF的长时间行为中的噪声。我们提出了一个详细的分析的功能形式，用于适应的活性碳纤维，这总是一个更有效的手段，以获得质量传输性能。我们使用拟合来估计输运性质的统计误差。我们将这种方法应用于铜和碳和氢的混合物的致密相关等离子体。这两个系统都在其ACF中显示了结构并表现出多个时间尺度。对于混合物中的每种组分，混合物含有不同结构形式的ACF。
In the warm dense matter (WDM) regime, material properties like diffusion and viscosity can be obtained from lengthy quantum molecular dynamics simulations, where the quantum behavior of the electrons is represented using either Kohn-Sham or orbital-free density functional theory. To reduce the simulation duration, we fit the time dependence of the autocorrelation functions (ACFs) and then use the fit to find values of the diffusion and viscosity. This fitting procedure avoids noise in the long time behavior of the ACFs. We present a detailed analysis of the functional form used to fit the ACFs, which is always a more efficient means to obtain mass transport properties. We use the fits to estimate the statistical error of the transport properties. We apply this methodology to a dense correlated plasma of copper and a mixture of carbon and hydrogen. Both systems show structure in their ACFs and exhibit multiple time scales. The mixture contains different structural forms of the ACFs for each component in the mixture.