CsSbSI2 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 6-coordinate geometry to one I(3), one I(6), two equivalent I(1), and two equivalent I(2) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one S(1), one I(3), one I(5), one I(6), two equivalent I(1), and two equivalent I(2) atoms. In the third Cs site, Cs(3) is bonded in a 11-coordinate geometry to two equivalent S(2), one I(3), one I(5), one I(6), two equivalent I(1), two equivalent I(4), and two equivalent I(7) atoms. In the fourth Cs site, Cs(4) is bonded to one S(1), two equivalent S(2), one I(3), one I(5), one I(6), two equivalent I(1), two equivalent I(4), and two equivalent I(7) atoms to form distorted corner-sharing CsS3I9 cuboctahedra. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 4-coordinate geometry to one S(1), one S(2), one I(2), and one I(4) atom. In the second Sb site, Sb(2) is bonded in a 6-coordinate geometry to one S(2), one S(3), one I(1), one I(5), one I(6), and one I(7) atom. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 2-coordinate geometry to one Cs(2), one Cs(4), and two equivalent Sb(1) atoms. In the second S site, S(2) is bonded in a 2-coordinate geometry to one Cs(3), one Cs(4), one Sb(1), and one Sb(2) atom. In the third S site, S(3) is bonded in a linear geometry to two equivalent Sb(2) atoms. There are seven inequivalent I sites. In the first I site, I(4) is bonded to two equivalent Cs(3), two equivalent Cs(4), and two equivalent Sb(1) atoms to form distorted ICs4Sb2 octahedra that share corners with two equivalent I(2)Cs4Sb2 octahedra, corners with four equivalent I(6)Cs4Sb2 octahedra, corners with four equivalent I(7)Cs4Sb2 octahedra, corners with four equivalent I(1)Cs4Sb square pyramids, edges with two equivalent I(4)Cs4Sb2 octahedra, edges with two equivalent I(7)Cs4Sb2 octahedra, and edges with two equivalent I(1)Cs4Sb square pyramids. The corner-sharing octahedral tilt angles range from 2-59°. In the second I site, I(5) is bonded in a 2-coordinate geometry to one Cs(2), one Cs(3), one Cs(4), and two equivalent Sb(2) atoms. In the third I site, I(6) is bonded to one Cs(1), one Cs(2), one Cs(3), one Cs(4), and two equivalent Sb(2) atoms to form distorted ICs4Sb2 octahedra that share corners with four equivalent I(2)Cs4Sb2 octahedra, corners with four equivalent I(4)Cs4Sb2 octahedra, corners with four equivalent I(1)Cs4Sb square pyramids, faces with two equivalent I(7)Cs4Sb2 octahedra, and faces with two equivalent I(1)Cs4Sb square pyramids. The corner-sharing octahedral tilt angles range from 58-59°. In the fourth I site, I(7) is bonded to two equivalent Cs(3), two equivalent Cs(4), and two equivalent Sb(2) atoms to form ICs4Sb2 octahedra that share corners with four equivalent I(4)Cs4Sb2 octahedra, corners with four equivalent I(1)Cs4Sb square pyramids, edges with two equivalent I(4)Cs4Sb2 octahedra, edges with two equivalent I(7)Cs4Sb2 octahedra, faces with two equivalent I(6)Cs4Sb2 octahedra, and faces with two equivalent I(1)Cs4Sb square pyramids. The corner-sharing octahedral tilt angles range from 2-5°. In the fifth I site, I(1) is bonded to one Cs(1), one Cs(2), one Cs(3), one Cs(4), and one Sb(2) atom to form distorted ICs4Sb square pyramids that share corners with two equivalent I(2)Cs4Sb2 octahedra, corners with two equivalent I(4)Cs4Sb2 octahedra, corners with two equivalent I(6)Cs4Sb2 octahedra, corners with two equivalent I(7)Cs4Sb2 octahedra,  an edgeedge with one I(2)Cs4Sb2 octahedra,  an edgeedge with one I(4)Cs4Sb2 octahedra, edges with two equivalent I(1)Cs4Sb square pyramids,  a faceface with one I(6)Cs4Sb2 octahedra, and  a faceface with one I(7)Cs4Sb2 octahedra. The corner-sharing octahedral tilt angles range from 54-66°. In the sixth I site, I(2) is bonded to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Sb(1) atoms to form distorted ICs4Sb2 octahedra that share corners with two equivalent I(4)Cs4Sb2 octahedra, corners with four equivalent I(6)Cs4Sb2 octahedra, corners with four equivalent I(1)Cs4Sb square pyramids, edges with two equivalent I(2)Cs4Sb2 octahedra, and edges with two equivalent I(1)Cs4Sb square pyramids. The corner-sharing octahedral tilt angles range from 32-59°. In the seventh I site, I(3) is bonded in a distorted square co-planar geometry to one Cs(1), one Cs(2), one Cs(3), and one Cs(4) atom.
CsSbSI2 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 6-coordinate geometry to one I(3), one I(6), two equivalent I(1), and two equivalent I(2) atoms. The Cs(1)-I(3) bond length is 3.95 Å. The Cs(1)-I(6) bond length is 4.05 Å. Both Cs(1)-I(1) bond lengths are 4.20 Å. Both Cs(1)-I(2) bond lengths are 4.09 Å. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one S(1), one I(3), one I(5), one I(6), two equivalent I(1), and two equivalent I(2) atoms. The Cs(2)-S(1) bond length is 3.94 Å. The Cs(2)-I(3) bond length is 4.13 Å. The Cs(2)-I(5) bond length is 4.16 Å. The Cs(2)-I(6) bond length is 4.26 Å. Both Cs(2)-I(1) bond lengths are 4.13 Å. Both Cs(2)-I(2) bond lengths are 4.16 Å. In the third Cs site, Cs(3) is bonded in a 11-coordinate geometry to two equivalent S(2), one I(3), one I(5), one I(6), two equivalent I(1), two equivalent I(4), and two equivalent I(7) atoms. Both Cs(3)-S(2) bond lengths are 4.14 Å. The Cs(3)-I(3) bond length is 3.99 Å. The Cs(3)-I(5) bond length is 4.53 Å. The Cs(3)-I(6) bond length is 4.08 Å. Both Cs(3)-I(1) bond lengths are 4.45 Å. Both Cs(3)-I(4) bond lengths are 4.18 Å. Both Cs(3)-I(7) bond lengths are 4.27 Å. In the fourth Cs site, Cs(4) is bonded to one S(1), two equivalent S(2), one I(3), one I(5), one I(6), two equivalent I(1), two equivalent I(4), and two equivalent I(7) atoms to form distorted corner-sharing CsS3I9 cuboctahedra. The Cs(4)-S(1) bond length is 4.10 Å. Both Cs(4)-S(2) bond lengths are 4.19 Å. The Cs(4)-I(3) bond length is 4.22 Å. The Cs(4)-I(5) bond length is 4.18 Å. The Cs(4)-I(6) bond length is 4.36 Å. Both Cs(4)-I(1) bond lengths are 4.33 Å. Both Cs(4)-I(4) bond lengths are 4.24 Å. Both Cs(4)-I(7) bond lengths are 4.20 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 4-coordinate geometry to one S(1), one S(2), one I(2), and one I(4) atom. The Sb(1)-S(1) bond length is 2.57 Å. The Sb(1)-S(2) bond length is 2.36 Å. The Sb(1)-I(2) bond length is 3.10 Å. The Sb(1)-I(4) bond length is 3.12 Å. In the second Sb site, Sb(2) is bonded in a 6-coordinate geometry to one S(2), one S(3), one I(1), one I(5), one I(6), and one I(7) atom. The Sb(2)-S(2) bond length is 2.84 Å. The Sb(2)-S(3) bond length is 2.51 Å. The Sb(2)-I(1) bond length is 2.92 Å. The Sb(2)-I(5) bond length is 3.01 Å. The Sb(2)-I(6) bond length is 3.07 Å. The Sb(2)-I(7) bond length is 3.46 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 2-coordinate geometry to one Cs(2), one Cs(4), and two equivalent Sb(1) atoms. In the second S site, S(2) is bonded in a 2-coordinate geometry to one Cs(3), one Cs(4), one Sb(1), and one Sb(2) atom. In the third S site, S(3) is bonded in a linear geometry to two equivalent Sb(2) atoms. There are seven inequivalent I sites. In the first I site, I(4) is bonded to two equivalent Cs(3), two equivalent Cs(4), and two equivalent Sb(1) atoms to form distorted ICs4Sb2 octahedra that share corners with two equivalent I(2)Cs4Sb2 octahedra, corners with four equivalent I(6)Cs4Sb2 octahedra, corners with four equivalent I(7)Cs4Sb2 octahedra, corners with four equivalent I(1)Cs4Sb square pyramids, edges with two equivalent I(4)Cs4Sb2 octahedra, edges with two equivalent I(7)Cs4Sb2 octahedra, and edges with two equivalent I(1)Cs4Sb square pyramids. The corner-sharing octahedral tilt angles range from 2-59°. In the second I site, I(5) is bonded in a 2-coordinate geometry to one Cs(2), one Cs(3), one Cs(4), and two equivalent Sb(2) atoms. In the third I site, I(6) is bonded to one Cs(1), one Cs(2), one Cs(3), one Cs(4), and two equivalent Sb(2) atoms to form distorted ICs4Sb2 octahedra that share corners with four equivalent I(2)Cs4Sb2 octahedra, corners with four equivalent I(4)Cs4Sb2 octahedra, corners with four equivalent I(1)Cs4Sb square pyramids, faces with two equivalent I(7)Cs4Sb2 octahedra, and faces with two equivalent I(1)Cs4Sb square pyramids. The corner-sharing octahedral tilt angles range from 58-59°. In the fourth I site, I(7) is bonded to two equivalent Cs(3), two equivalent Cs(4), and two equivalent Sb(2) atoms to form ICs4Sb2 octahedra that share corners with four equivalent I(4)Cs4Sb2 octahedra, corners with four equivalent I(1)Cs4Sb square pyramids, edges with two equivalent I(4)Cs4Sb2 octahedra, edges with two equivalent I(7)Cs4Sb2 octahedra, faces with two equivalent I(6)Cs4Sb2 octahedra, and faces with two equivalent I(1)Cs4Sb square pyramids. The corner-sharing octahedral tilt angles range from 2-5°. In the fifth I site, I(1) is bonded to one Cs(1), one Cs(2), one Cs(3), one Cs(4), and one Sb(2) atom to form distorted ICs4Sb square pyramids that share corners with two equivalent I(2)Cs4Sb2 octahedra, corners with two equivalent I(4)Cs4Sb2 octahedra, corners with two equivalent I(6)Cs4Sb2 octahedra, corners with two equivalent I(7)Cs4Sb2 octahedra,  an edgeedge with one I(2)Cs4Sb2 octahedra,  an edgeedge with one I(4)Cs4Sb2 octahedra, edges with two equivalent I(1)Cs4Sb square pyramids,  a faceface with one I(6)Cs4Sb2 octahedra, and  a faceface with one I(7)Cs4Sb2 octahedra. The corner-sharing octahedral tilt angles range from 54-66°. In the sixth I site, I(2) is bonded to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Sb(1) atoms to form distorted ICs4Sb2 octahedra that share corners with two equivalent I(4)Cs4Sb2 octahedra, corners with four equivalent I(6)Cs4Sb2 octahedra, corners with four equivalent I(1)Cs4Sb square pyramids, edges with two equivalent I(2)Cs4Sb2 octahedra, and edges with two equivalent I(1)Cs4Sb square pyramids. The corner-sharing octahedral tilt angles range from 32-59°. In the seventh I site, I(3) is bonded in a distorted square co-planar geometry to one Cs(1), one Cs(2), one Cs(3), and one Cs(4) atom.