Abstract: The NaF-CaF_2 system has been studied by molecular dynamics simulation.The pair correlation functions between cations and anions and the bond angle distributions of cation and anion triplets have been obtained.The bridging and complexing in the system are discussed based on the pair correlation functions and bond angle distributions.The results simulated show that the F~- ions around a Ca~(2+)ion do not form tetrahedron coordination,so some of small complexing clusters such as CaF_4~(2-)are hardly found.A possible structure of F~- ions around Ca~(2+)ions is that three Ca~(2+)ions constitute an equilateral triangle through three Ca-F-Ca bridges and two F~- ions are located over and under the center of the right triangle,respectively.Meanwhile,on the outside of the triangle,every Ca~(2+)ion has other two F~- ions as its neighbors.

Key words: NaF-CaF_2 system, structure of molten salt solution, molecualr dynamics simulation