Li Xuejiao, Song Jia, Shi Shuping, Yan Liuming, Zhang Zhaochun, Jiang Tao, Peng Shuming
Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics , Mianyang 621900, China.
J Phys Chem A. 2017 Jan 26;121(3):571-578. doi: 10.1021/acs.jpca.6b10193. Epub 2017 Jan 17.
The dynamic fluctuation of the U coordination structure in a molten LiCl-KCl mixture was studied using first principles molecular dynamics (FPMD) simulations. The radial distribution function, probability distribution of coordination numbers, fluctuation of coordination number and cage volume, self-diffusion coefficient and solvodynamic mean radius of U, dynamics of the nearest U-Cl distances, and van Hove function were evaluated. It was revealed that fast exchange of Cl occurred between the first and second coordination shells of U accompanied with fast fluctuation of coordination number and rearrangement of coordination structure. It was concluded that 6-fold coordination structure dominated the coordination structure of U in the molten LiCl-KCl-UCl mixture and a high temperature was conducive to the formation of low coordinated structure.
采用第一性原理分子动力学（FPMD）模拟研究了熔融LiCl-KCl混合物中U配位结构的动态波动。评估了径向分布函数、配位数的概率分布、配位数和笼体积的波动、U的自扩散系数和溶剂动力学平均半径、最近的U-Cl距离的动力学以及范霍夫函数。结果表明，Cl在U的第一和第二配位壳层之间快速交换，伴随着配位数的快速波动和配位结构的重排。得出的结论是，在熔融LiCl-KCl-UCl混合物中，六重配位结构主导了U的配位结构，高温有利于形成低配位结构。
