Structural and dynamical properties of -CuI: a molecular dynamics study

A constant temperature - constant volume molecular dynamics simulation has been applied to superionic CuI ( -CuI) with the use of a pairwise interionic potential. Excellent agreement between the calculated value and experimental value of the cation diffusion coefficient is obtained. About 35% of cations are resident in octahedra formed by cage ions (I ions) but a small cation occupation at octahedral sites was found. The remaining cations are distributed among tetrahedra including and sites with different weights, where and denote tetrahedral sites which are occupied by ions and vacant in the zincblende structure, respectively. The jump frequency and the correlation factor f of mobile ions are evaluated with the use of the polyhedron analysis method. Quantities , and f evaluated by the simulation reproduce well the relation under the assumption of constant r.