Cu4I3Br is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent I(2), three equivalent I(1), and one Br(1) atom to form CuI5Br octahedra that share corners with three equivalent Cu(2)I4Br2 octahedra, corners with three equivalent Cu(1)I5Br octahedra, edges with five equivalent Cu(1)I5Br octahedra, and edges with seven equivalent Cu(2)I4Br2 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second Cu site, Cu(2) is bonded to one I(2), three equivalent I(1), and two equivalent Br(1) atoms to form CuI4Br2 octahedra that share corners with three equivalent Cu(2)I4Br2 octahedra, corners with three equivalent Cu(1)I5Br octahedra, edges with five equivalent Cu(2)I4Br2 octahedra, and edges with seven equivalent Cu(1)I5Br octahedra. The corner-sharing octahedral tilt angles range from 0-1°. There are two inequivalent I sites. In the first I site, I(1) is bonded to three equivalent Cu(1) and three equivalent Cu(2) atoms to form ICu6 octahedra that share corners with three equivalent I(2)Cu6 octahedra, corners with three equivalent Br(1)Cu6 octahedra, edges with three equivalent I(2)Cu6 octahedra, edges with three equivalent Br(1)Cu6 octahedra, and edges with six equivalent I(1)Cu6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second I site, I(2) is bonded to two equivalent Cu(2) and four equivalent Cu(1) atoms to form ICu6 octahedra that share corners with six equivalent I(1)Cu6 octahedra, edges with two equivalent I(2)Cu6 octahedra, edges with four equivalent Br(1)Cu6 octahedra, and edges with six equivalent I(1)Cu6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. Br(1) is bonded to two equivalent Cu(1) and four equivalent Cu(2) atoms to form BrCu6 octahedra that share corners with six equivalent I(1)Cu6 octahedra, edges with two equivalent Br(1)Cu6 octahedra, edges with four equivalent I(2)Cu6 octahedra, and edges with six equivalent I(1)Cu6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°.
Cu4I3Br is Caswellsilverite-like structured and crystallizes in the monoclinic C2/m space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent I(2), three equivalent I(1), and one Br(1) atom to form CuI5Br octahedra that share corners with three equivalent Cu(2)I4Br2 octahedra, corners with three equivalent Cu(1)I5Br octahedra, edges with five equivalent Cu(1)I5Br octahedra, and edges with seven equivalent Cu(2)I4Br2 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. Both Cu(1)-I(2) bond lengths are 2.84 Å. There are two shorter (2.83 Å) and one longer (2.86 Å) Cu(1)-I(1) bond length. The Cu(1)-Br(1) bond length is 2.82 Å. In the second Cu site, Cu(2) is bonded to one I(2), three equivalent I(1), and two equivalent Br(1) atoms to form CuI4Br2 octahedra that share corners with three equivalent Cu(2)I4Br2 octahedra, corners with three equivalent Cu(1)I5Br octahedra, edges with five equivalent Cu(2)I4Br2 octahedra, and edges with seven equivalent Cu(1)I5Br octahedra. The corner-sharing octahedral tilt angles range from 0-1°. The Cu(2)-I(2) bond length is 2.83 Å. There is one shorter (2.80 Å) and two longer (2.84 Å) Cu(2)-I(1) bond lengths. Both Cu(2)-Br(1) bond lengths are 2.82 Å. There are two inequivalent I sites. In the first I site, I(1) is bonded to three equivalent Cu(1) and three equivalent Cu(2) atoms to form ICu6 octahedra that share corners with three equivalent I(2)Cu6 octahedra, corners with three equivalent Br(1)Cu6 octahedra, edges with three equivalent I(2)Cu6 octahedra, edges with three equivalent Br(1)Cu6 octahedra, and edges with six equivalent I(1)Cu6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. In the second I site, I(2) is bonded to two equivalent Cu(2) and four equivalent Cu(1) atoms to form ICu6 octahedra that share corners with six equivalent I(1)Cu6 octahedra, edges with two equivalent I(2)Cu6 octahedra, edges with four equivalent Br(1)Cu6 octahedra, and edges with six equivalent I(1)Cu6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°. Br(1) is bonded to two equivalent Cu(1) and four equivalent Cu(2) atoms to form BrCu6 octahedra that share corners with six equivalent I(1)Cu6 octahedra, edges with two equivalent Br(1)Cu6 octahedra, edges with four equivalent I(2)Cu6 octahedra, and edges with six equivalent I(1)Cu6 octahedra. The corner-sharing octahedral tilt angles range from 0-1°.