Crystal Structure of β-CuI

The crystal structure of β-CuI at 400°C has been refined from powder crystal X-ray diffraction data. The crystal belongs to the trigonal system with the space group C 1 3v -P3m1, and has lattice constants of a =4.279±0.002 A, c =7.168±0.007 A. The low temperature phase of solid electrolytes is often of tetrahedral structure such as zinc-blende or wurtzite. The structure of the β-CuI includes the ordered arrangement of Cu + ions surrounded by tetrahedra of I - ions.