Physical and Life Sciences, Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
J Chem Phys. 2009 Nov 28;131(20):204103. doi: 10.1063/1.3262710.
We present a straightforward method for the inclusion of quantum nuclear vibrational effects in molecular dynamics calculations of shock Hugoniot temperatures. Using a Gruneisen equation of state and a quasiharmonic approximation to the vibrational energies, we derive a simple, postprocessing method for calculation of the quantum corrected Hugoniot temperatures. We have used our novel technique on ab initio simulations of shock compressed water and methane. Our results indicate significantly closer agreement with all available experimental temperature data for these two systems. Our formalism can be easily applied to a number of different shock compressed molecular liquids or solids, and has the potential to decrease the large uncertainties inherent in many experimental Hugoniot temperature measurements of these systems.
我们提出了一种在分子动力学计算冲击压缩 Hugoniot 温度时纳入量子核振动效应的直接方法。通过使用 Grüneisen 状态方程和振动能的准谐近似，我们推导出了一种简单的后处理方法，用于计算量子修正的 Hugoniot 温度。我们已经在冲击压缩水和甲烷的从头算模拟中使用了我们的新技术。我们的结果表明，与这两个系统的所有可用实验温度数据更接近。我们的形式主义可以很容易地应用于许多不同的冲击压缩分子液体或固体，并且有可能降低这些系统许多实验 Hugoniot 温度测量中固有的大不确定性。
