Cu3Bi2S3Br2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent S(1) and two equivalent Br(2) atoms. In the second Cu site, Cu(2) is bonded to one S(3), two equivalent S(2), and one Br(2) atom to form corner-sharing CuS3Br tetrahedra. In the third Cu site, Cu(3) is bonded in a trigonal planar geometry to one S(3) and two equivalent S(1) atoms. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 7-coordinate geometry to one S(1), two equivalent S(3), two equivalent Br(1), and two equivalent Br(2) atoms. In the second Bi site, Bi(2) is bonded in a 4-coordinate geometry to two equivalent S(2) and two equivalent Br(1) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Cu(1), two equivalent Cu(3), and one Bi(1) atom to form distorted SCu4Bi trigonal bipyramids that share corners with four equivalent S(3)Cu2Bi2 tetrahedra and corners with four equivalent S(1)Cu4Bi trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Cu(2) and two equivalent Bi(2) atoms to form a mixture of corner and edge-sharing SCu2Bi2 tetrahedra. In the third S site, S(3) is bonded to one Cu(2), one Cu(3), and two equivalent Bi(1) atoms to form SCu2Bi2 tetrahedra that share corners with two equivalent S(2)Cu2Bi2 tetrahedra, corners with two equivalent S(3)Cu2Bi2 tetrahedra, and corners with four equivalent S(1)Cu4Bi trigonal bipyramids. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded in a 4-coordinate geometry to two equivalent Bi(1) and two equivalent Bi(2) atoms. In the second Br site, Br(2) is bonded in a 3-coordinate geometry to one Cu(2), two equivalent Cu(1), and two equivalent Bi(1) atoms.
Cu3Bi2S3Br2 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent S(1) and two equivalent Br(2) atoms. There is one shorter (2.24 Å) and one longer (2.33 Å) Cu(1)-S(1) bond length. There is one shorter (2.66 Å) and one longer (2.68 Å) Cu(1)-Br(2) bond length. In the second Cu site, Cu(2) is bonded to one S(3), two equivalent S(2), and one Br(2) atom to form corner-sharing CuS3Br tetrahedra. The Cu(2)-S(3) bond length is 2.27 Å. There is one shorter (2.27 Å) and one longer (2.28 Å) Cu(2)-S(2) bond length. The Cu(2)-Br(2) bond length is 2.81 Å. In the third Cu site, Cu(3) is bonded in a trigonal planar geometry to one S(3) and two equivalent S(1) atoms. The Cu(3)-S(3) bond length is 2.24 Å. There is one shorter (2.23 Å) and one longer (2.24 Å) Cu(3)-S(1) bond length. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a 7-coordinate geometry to one S(1), two equivalent S(3), two equivalent Br(1), and two equivalent Br(2) atoms. The Bi(1)-S(1) bond length is 2.70 Å. There is one shorter (2.67 Å) and one longer (2.70 Å) Bi(1)-S(3) bond length. There is one shorter (3.26 Å) and one longer (3.30 Å) Bi(1)-Br(1) bond length. There is one shorter (3.31 Å) and one longer (3.41 Å) Bi(1)-Br(2) bond length. In the second Bi site, Bi(2) is bonded in a 4-coordinate geometry to two equivalent S(2) and two equivalent Br(1) atoms. There is one shorter (2.66 Å) and one longer (2.70 Å) Bi(2)-S(2) bond length. There is one shorter (3.24 Å) and one longer (3.36 Å) Bi(2)-Br(1) bond length. There are three inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Cu(1), two equivalent Cu(3), and one Bi(1) atom to form distorted SCu4Bi trigonal bipyramids that share corners with four equivalent S(3)Cu2Bi2 tetrahedra and corners with four equivalent S(1)Cu4Bi trigonal bipyramids. In the second S site, S(2) is bonded to two equivalent Cu(2) and two equivalent Bi(2) atoms to form a mixture of corner and edge-sharing SCu2Bi2 tetrahedra. In the third S site, S(3) is bonded to one Cu(2), one Cu(3), and two equivalent Bi(1) atoms to form SCu2Bi2 tetrahedra that share corners with two equivalent S(2)Cu2Bi2 tetrahedra, corners with two equivalent S(3)Cu2Bi2 tetrahedra, and corners with four equivalent S(1)Cu4Bi trigonal bipyramids. There are two inequivalent Br sites. In the first Br site, Br(1) is bonded in a 4-coordinate geometry to two equivalent Bi(1) and two equivalent Bi(2) atoms. In the second Br site, Br(2) is bonded in a 3-coordinate geometry to one Cu(2), two equivalent Cu(1), and two equivalent Bi(1) atoms.