CuCr2Se3Br is Spinel-derived structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to six equivalent Se(1) atoms to form CrSe6 octahedra that share corners with six equivalent Cu(1)Se3Br tetrahedra and edges with six equivalent Cr(2)Se4Br2 octahedra. In the second Cr site, Cr(2) is bonded to four equivalent Se(1) and two equivalent Br(1) atoms to form CrSe4Br2 octahedra that share corners with six equivalent Cu(1)Se3Br tetrahedra, edges with two equivalent Cr(1)Se6 octahedra, and edges with four equivalent Cr(2)Se4Br2 octahedra. Cu(1) is bonded to three equivalent Se(1) and one Br(1) atom to form CuSe3Br tetrahedra that share corners with three equivalent Cr(1)Se6 octahedra and corners with nine equivalent Cr(2)Se4Br2 octahedra. The corner-sharing octahedral tilt angles range from 53-61°. Se(1) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(2), and one Cu(1) atom. Br(1) is bonded in a rectangular see-saw-like geometry to three equivalent Cr(2) and one Cu(1) atom.
CuCr2Se3Br is Spinel-derived structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to six equivalent Se(1) atoms to form CrSe6 octahedra that share corners with six equivalent Cu(1)Se3Br tetrahedra and edges with six equivalent Cr(2)Se4Br2 octahedra. All Cr(1)-Se(1) bond lengths are 2.54 Å. In the second Cr site, Cr(2) is bonded to four equivalent Se(1) and two equivalent Br(1) atoms to form CrSe4Br2 octahedra that share corners with six equivalent Cu(1)Se3Br tetrahedra, edges with two equivalent Cr(1)Se6 octahedra, and edges with four equivalent Cr(2)Se4Br2 octahedra. All Cr(2)-Se(1) bond lengths are 2.54 Å. Both Cr(2)-Br(1) bond lengths are 2.58 Å. Cu(1) is bonded to three equivalent Se(1) and one Br(1) atom to form CuSe3Br tetrahedra that share corners with three equivalent Cr(1)Se6 octahedra and corners with nine equivalent Cr(2)Se4Br2 octahedra. The corner-sharing octahedral tilt angles range from 53-61°. All Cu(1)-Se(1) bond lengths are 2.39 Å. The Cu(1)-Br(1) bond length is 2.62 Å. Se(1) is bonded in a rectangular see-saw-like geometry to one Cr(1), two equivalent Cr(2), and one Cu(1) atom. Br(1) is bonded in a rectangular see-saw-like geometry to three equivalent Cr(2) and one Cu(1) atom.