K3Sn2S3O3Br crystallizes in the monoclinic P2_1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a distorted trigonal non-coplanar geometry to one Sn(1), one O(1), one O(2), and one O(3) atom. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent S(3), one O(1), one O(3), and two equivalent Br(1) atoms. In the third K site, K(3) is bonded in a 6-coordinate geometry to two equivalent S(1), one O(1), one O(2), and two equivalent Br(1) atoms. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 4-coordinate geometry to one K(1), one S(1), one S(2), and one S(3) atom. In the second Sn site, Sn(2) is bonded in a distorted single-bond geometry to one O(2), one O(3), and two equivalent Br(1) atoms. There are three inequivalent S sites. In the first S site, S(1) is bonded in a distorted single-bond geometry to two equivalent K(3), one Sn(1), and one O(1) atom. In the second S site, S(2) is bonded in a distorted single-bond geometry to one Sn(1) and one O(2) atom. In the third S site, S(3) is bonded in a distorted single-bond geometry to two equivalent K(2), one Sn(1), and one O(3) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded to one K(1), one K(2), one K(3), and one S(1) atom to form distorted OK3S tetrahedra that share corners with two equivalent Br(1)K4Sn2 octahedra, corners with two equivalent O(3)K2SnS tetrahedra, and  an edgeedge with one Br(1)K4Sn2 octahedra. The corner-sharing octahedral tilt angles range from 39-80°. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(3), one Sn(2), and one S(2) atom. In the third O site, O(3) is bonded to one K(1), one K(2), one Sn(2), and one S(3) atom to form distorted OK2SnS tetrahedra that share corners with two equivalent Br(1)K4Sn2 octahedra, corners with two equivalent O(1)K3S tetrahedra, and  an edgeedge with one Br(1)K4Sn2 octahedra. The corner-sharing octahedral tilt angles range from 48-81°. Br(1) is bonded to two equivalent K(2), two equivalent K(3), and two equivalent Sn(2) atoms to form distorted BrK4Sn2 octahedra that share corners with two equivalent O(3)K2SnS tetrahedra, corners with two equivalent O(1)K3S tetrahedra,  an edgeedge with one O(3)K2SnS tetrahedra,  an edgeedge with one O(1)K3S tetrahedra, and faces with two equivalent Br(1)K4Sn2 octahedra.
K3Sn2S3O3Br crystallizes in the monoclinic P2_1 space group. There are three inequivalent K sites. In the first K site, K(1) is bonded in a distorted trigonal non-coplanar geometry to one Sn(1), one O(1), one O(2), and one O(3) atom. The K(1)-Sn(1) bond length is 3.64 Å. The K(1)-O(1) bond length is 2.60 Å. The K(1)-O(2) bond length is 2.67 Å. The K(1)-O(3) bond length is 2.80 Å. In the second K site, K(2) is bonded in a 6-coordinate geometry to two equivalent S(3), one O(1), one O(3), and two equivalent Br(1) atoms. There is one shorter (3.42 Å) and one longer (3.44 Å) K(2)-S(3) bond length. The K(2)-O(1) bond length is 2.68 Å. The K(2)-O(3) bond length is 3.04 Å. There is one shorter (3.18 Å) and one longer (3.19 Å) K(2)-Br(1) bond length. In the third K site, K(3) is bonded in a 6-coordinate geometry to two equivalent S(1), one O(1), one O(2), and two equivalent Br(1) atoms. There is one shorter (3.25 Å) and one longer (3.63 Å) K(3)-S(1) bond length. The K(3)-O(1) bond length is 2.87 Å. The K(3)-O(2) bond length is 2.88 Å. There is one shorter (3.13 Å) and one longer (3.27 Å) K(3)-Br(1) bond length. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 4-coordinate geometry to one K(1), one S(1), one S(2), and one S(3) atom. The Sn(1)-S(1) bond length is 2.58 Å. The Sn(1)-S(2) bond length is 2.70 Å. The Sn(1)-S(3) bond length is 2.62 Å. In the second Sn site, Sn(2) is bonded in a distorted single-bond geometry to one O(2), one O(3), and two equivalent Br(1) atoms. The Sn(2)-O(2) bond length is 2.79 Å. The Sn(2)-O(3) bond length is 2.20 Å. There is one shorter (3.09 Å) and one longer (3.26 Å) Sn(2)-Br(1) bond length. There are three inequivalent S sites. In the first S site, S(1) is bonded in a distorted single-bond geometry to two equivalent K(3), one Sn(1), and one O(1) atom. The S(1)-O(1) bond length is 1.61 Å. In the second S site, S(2) is bonded in a distorted single-bond geometry to one Sn(1) and one O(2) atom. The S(2)-O(2) bond length is 1.61 Å. In the third S site, S(3) is bonded in a distorted single-bond geometry to two equivalent K(2), one Sn(1), and one O(3) atom. The S(3)-O(3) bond length is 1.69 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one K(1), one K(2), one K(3), and one S(1) atom to form distorted OK3S tetrahedra that share corners with two equivalent Br(1)K4Sn2 octahedra, corners with two equivalent O(3)K2SnS tetrahedra, and  an edgeedge with one Br(1)K4Sn2 octahedra. The corner-sharing octahedral tilt angles range from 39-80°. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(3), one Sn(2), and one S(2) atom. In the third O site, O(3) is bonded to one K(1), one K(2), one Sn(2), and one S(3) atom to form distorted OK2SnS tetrahedra that share corners with two equivalent Br(1)K4Sn2 octahedra, corners with two equivalent O(1)K3S tetrahedra, and  an edgeedge with one Br(1)K4Sn2 octahedra. The corner-sharing octahedral tilt angles range from 48-81°. Br(1) is bonded to two equivalent K(2), two equivalent K(3), and two equivalent Sn(2) atoms to form distorted BrK4Sn2 octahedra that share corners with two equivalent O(3)K2SnS tetrahedra, corners with two equivalent O(1)K3S tetrahedra,  an edgeedge with one O(3)K2SnS tetrahedra,  an edgeedge with one O(1)K3S tetrahedra, and faces with two equivalent Br(1)K4Sn2 octahedra.