Materials Data on Cu4IBr3 by Materials Project
Cu4IBr3 is Caswellsilverite-like structured and crystallizes in the trigonal R-3m space group. The structure is three-dimensional. there are two inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded to six Br1- atoms to form a mixture of edge and corner-sharing CuBr6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are three shorter (2.70 Å) and three longer (2.73 Å) Cu–Br bond lengths. In the second Cu1+ site, Cu1+ is bonded to three equivalent I1- and three equivalent Br1- atoms to form a mixture of edge and corner-sharing CuI3Br3 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. All Cu–I bond lengths are 2.76 Å. All Cu–Br bond lengths are 2.75 Å. I1- is bonded to six equivalent Cu1+ atoms to form ICu6 octahedra that share corners with six equivalent BrCu6 octahedra, edges with six equivalent ICu6 octahedra, and edges with six equivalent BrCu6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded to six Cu1+ atoms to form BrCu6 octahedra that share corners with three equivalent ICu6 octahedra, corners with three equivalent BrCu6 octahedra, edges with three equivalent ICu6 octahedra, and edges with nine BrCu6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the second Br1- site, Br1- is bonded to six equivalent Cu1+ atoms to form a mixture of edge and corner-sharing BrCu6 octahedra. The corner-sharing octahedral tilt angles are 1°.