Multi-charge-state molecular dynamics and self-diffusion coefficient in the warm dense matter regime

作者：Fu, Yongsheng; Hou, Yong^*; Kang, Dongdong; Gao, Cheng; Jin, Fengtao; Yuan, Jianmin^*

来源：Physics of Plasmas, 2018, 25(1): 012701.

DOI：10.1063/1.5000757

We present a multi-ion molecular dynamics (MIMD) simulation and apply it to calculating the self-diffusion coefficients of ions with different charge-states in the warm dense matter (WDM) regime. First, the method is used for the self-consistent calculation of electron structures of different charge-state ions in the ion sphere, with the ion-sphere radii being determined by the plasma density and the ion charges. The ionic fraction is then obtained by solving the Saha equation, taking account of interactions among different charge-state ions in the system, and ion-ion pair potentials are computed using the modified Gordon-Kim method in the framework of temperature-dependent density functional theory on the basis of the electron structures. Finally, MIMD is used to calculate ionic self-diffusion coefficients from the velocity correlation function according to the Green-Kubo relation. A comparison with the results of the average-atom model shows that different statistical processes will influence the ionic diffusion coefficient in the WDM regime. Published by AIP Publishing.

• 出版日期2018-1
• 单位中国人民解放军国防科学技术大学; 中国工程物理研究院