In2S3 crystallizes in the monoclinic Cm space group. There are seven inequivalent In sites. In the first In site, In(1) is bonded in a trigonal planar geometry to one S(2) and two equivalent S(4) atoms. In the second In site, In(2) is bonded in a trigonal non-coplanar geometry to one S(5) and two equivalent S(1) atoms. In the third In site, In(3) is bonded to one S(2), one S(6), two equivalent S(1), and two equivalent S(4) atoms to form InS6 octahedra that share corners with three equivalent In(6)S4 tetrahedra,  an edgeedge with one In(4)S6 octahedra, and edges with two equivalent In(5)S6 octahedra. In the fourth In site, In(4) is bonded to one S(3), one S(8), two equivalent S(4), and two equivalent S(7) atoms to form InS6 octahedra that share  a cornercorner with one In(6)S4 tetrahedra, corners with two equivalent In(7)S4 tetrahedra,  an edgeedge with one In(3)S6 octahedra, and edges with four equivalent In(5)S6 octahedra. In the fifth In site, In(5) is bonded to one S(2), one S(3), one S(4), one S(7), one S(8), and one S(9) atom to form InS6 octahedra that share  a cornercorner with one In(6)S4 tetrahedra, corners with two equivalent In(7)S4 tetrahedra,  an edgeedge with one In(3)S6 octahedra, edges with two equivalent In(4)S6 octahedra, and edges with two equivalent In(5)S6 octahedra. In the sixth In site, In(6) is bonded to one S(6), one S(8), and two equivalent S(1) atoms to form corner-sharing InS4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-69°. In the seventh In site, In(7) is bonded to one S(5), one S(9), and two equivalent S(7) atoms to form corner-sharing InS4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-62°. There are nine inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to one In(2), one In(3), and one In(6) atom. In the second S site, S(2) is bonded to one In(1), one In(3), and two equivalent In(5) atoms to form a mixture of distorted edge and corner-sharing SIn4 tetrahedra. In the third S site, S(3) is bonded in a distorted trigonal non-coplanar geometry to one In(4) and two equivalent In(5) atoms. In the fourth S site, S(4) is bonded to one In(1), one In(3), one In(4), and one In(5) atom to form a mixture of distorted edge and corner-sharing SIn4 tetrahedra. In the fifth S site, S(5) is bonded in a bent 120 degrees geometry to one In(2) and one In(7) atom. In the sixth S site, S(6) is bonded in a water-like geometry to one In(3) and one In(6) atom. In the seventh S site, S(7) is bonded in a distorted trigonal planar geometry to one In(4), one In(5), and one In(7) atom. In the eighth S site, S(8) is bonded in a rectangular see-saw-like geometry to one In(4), one In(6), and two equivalent In(5) atoms. In the ninth S site, S(9) is bonded in a trigonal non-coplanar geometry to one In(7) and two equivalent In(5) atoms.
In2S3 crystallizes in the monoclinic Cm space group. There are seven inequivalent In sites. In the first In site, In(1) is bonded in a trigonal planar geometry to one S(2) and two equivalent S(4) atoms. The In(1)-S(2) bond length is 2.45 Å. Both In(1)-S(4) bond lengths are 2.43 Å. In the second In site, In(2) is bonded in a trigonal non-coplanar geometry to one S(5) and two equivalent S(1) atoms. The In(2)-S(5) bond length is 2.35 Å. Both In(2)-S(1) bond lengths are 2.50 Å. In the third In site, In(3) is bonded to one S(2), one S(6), two equivalent S(1), and two equivalent S(4) atoms to form InS6 octahedra that share corners with three equivalent In(6)S4 tetrahedra,  an edgeedge with one In(4)S6 octahedra, and edges with two equivalent In(5)S6 octahedra. The In(3)-S(2) bond length is 2.81 Å. The In(3)-S(6) bond length is 2.48 Å. Both In(3)-S(1) bond lengths are 2.65 Å. Both In(3)-S(4) bond lengths are 2.75 Å. In the fourth In site, In(4) is bonded to one S(3), one S(8), two equivalent S(4), and two equivalent S(7) atoms to form InS6 octahedra that share  a cornercorner with one In(6)S4 tetrahedra, corners with two equivalent In(7)S4 tetrahedra,  an edgeedge with one In(3)S6 octahedra, and edges with four equivalent In(5)S6 octahedra. The In(4)-S(3) bond length is 2.55 Å. The In(4)-S(8) bond length is 2.69 Å. Both In(4)-S(4) bond lengths are 2.80 Å. Both In(4)-S(7) bond lengths are 2.56 Å. In the fifth In site, In(5) is bonded to one S(2), one S(3), one S(4), one S(7), one S(8), and one S(9) atom to form InS6 octahedra that share  a cornercorner with one In(6)S4 tetrahedra, corners with two equivalent In(7)S4 tetrahedra,  an edgeedge with one In(3)S6 octahedra, edges with two equivalent In(4)S6 octahedra, and edges with two equivalent In(5)S6 octahedra. The In(5)-S(2) bond length is 2.73 Å. The In(5)-S(3) bond length is 2.55 Å. The In(5)-S(4) bond length is 2.77 Å. The In(5)-S(7) bond length is 2.57 Å. The In(5)-S(8) bond length is 2.74 Å. The In(5)-S(9) bond length is 2.57 Å. In the sixth In site, In(6) is bonded to one S(6), one S(8), and two equivalent S(1) atoms to form corner-sharing InS4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-69°. The In(6)-S(6) bond length is 2.39 Å. The In(6)-S(8) bond length is 2.54 Å. Both In(6)-S(1) bond lengths are 2.58 Å. In the seventh In site, In(7) is bonded to one S(5), one S(9), and two equivalent S(7) atoms to form corner-sharing InS4 tetrahedra. The corner-sharing octahedral tilt angles range from 59-62°. The In(7)-S(5) bond length is 2.47 Å. The In(7)-S(9) bond length is 2.46 Å. Both In(7)-S(7) bond lengths are 2.49 Å. There are nine inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to one In(2), one In(3), and one In(6) atom. In the second S site, S(2) is bonded to one In(1), one In(3), and two equivalent In(5) atoms to form a mixture of distorted edge and corner-sharing SIn4 tetrahedra. In the third S site, S(3) is bonded in a distorted trigonal non-coplanar geometry to one In(4) and two equivalent In(5) atoms. In the fourth S site, S(4) is bonded to one In(1), one In(3), one In(4), and one In(5) atom to form a mixture of distorted edge and corner-sharing SIn4 tetrahedra. In the fifth S site, S(5) is bonded in a bent 120 degrees geometry to one In(2) and one In(7) atom. In the sixth S site, S(6) is bonded in a water-like geometry to one In(3) and one In(6) atom. In the seventh S site, S(7) is bonded in a distorted trigonal planar geometry to one In(4), one In(5), and one In(7) atom. In the eighth S site, S(8) is bonded in a rectangular see-saw-like geometry to one In(4), one In(6), and two equivalent In(5) atoms. In the ninth S site, S(9) is bonded in a trigonal non-coplanar geometry to one In(7) and two equivalent In(5) atoms.