Lawrence Livermore National Laboratory, Livermore, California 94550, USA.
École Normale Supérieure de Lyon, Université Lyon 1, Laboratoire de Géologie de Lyon, CNRS UMR 5276, 69364 Lyon, Cedex 07, France.
Phys Rev E. 2023 Jan;107(1-2):015306. doi: 10.1103/PhysRevE.107.015306.
Accurately modeling dense plasmas over wide-ranging conditions of pressure and temperature is a grand challenge critically important to our understanding of stellar and planetary physics as well as inertial confinement fusion. In this work, we employ Kohn-Sham density functional theory (DFT) molecular dynamics (MD) to compute the properties of carbon at warm and hot dense matter conditions in the vicinity of the principal Hugoniot. In particular, we calculate the equation of state (EOS), Hugoniot, pair distribution functions, and diffusion coefficients for carbon at densities spanning 8 g/cm^{3} to 16 g/cm^{3} and temperatures ranging from 100 kK to 10 MK using the Spectral Quadrature method. We find that the computed EOS and Hugoniot are in good agreement with path integral Monte Carlo results and the sesame database. Additionally, we calculate the ion-ion structure factor and viscosity for selected points. All results presented are at the level of full Kohn-Sham DFT-MD, free of empirical parameters, average-atom, and orbital-free approximations employed previously at such conditions.
准确地模拟压力和温度范围广泛的稠密等离子体,是一项重大挑战,对我们理解恒星和行星物理学以及惯性约束聚变至关重要。在这项工作中,我们采用 Kohn-Sham 密度泛函理论(DFT)分子动力学(MD)来计算主激波附近温浓物质条件下碳的性质。具体来说,我们使用谱积分方法计算了密度范围为 8 g/cm^{3}至 16 g/cm^{3}、温度范围为 100 kK 至 10 MK 的碳的状态方程(EOS)、Hugoniot、配分函数和扩散系数。我们发现,计算得到的 EOS 和 Hugoniot 与路径积分蒙特卡罗结果和 sesame 数据库吻合良好。此外,我们还计算了选定点的离子-离子结构因子和粘度。所有呈现的结果均在全 Kohn-Sham DFT-MD 水平上,没有使用以前在这种条件下使用的经验参数、平均原子和无轨道近似。