In4Bi2S9 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent In sites. In the first In site, In(1) is bonded to one S(8), two equivalent S(6), and three equivalent S(1) atoms to form InS6 octahedra that share corners with two equivalent In(4)S6 octahedra, edges with four equivalent In(1)S6 octahedra, and edges with two equivalent In(3)S4 trigonal pyramids. The corner-sharing octahedral tilt angles are 51°. In the second In site, In(2) is bonded to one S(7), one S(9), two equivalent S(3), and two equivalent S(5) atoms to form InS6 octahedra that share corners with two equivalent In(4)S6 octahedra, corners with two equivalent Bi(2)S5 square pyramids, corners with two equivalent In(3)S4 trigonal pyramids, edges with two equivalent In(2)S6 octahedra, and edges with three equivalent Bi(2)S5 square pyramids. The corner-sharing octahedral tilt angles are 55°. In the third In site, In(3) is bonded to one S(3), one S(6), and two equivalent S(8) atoms to form distorted InS4 trigonal pyramids that share  a cornercorner with one In(4)S6 octahedra, corners with two equivalent In(2)S6 octahedra, corners with two equivalent In(3)S4 trigonal pyramids, and edges with two equivalent In(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 66-70°. In the fourth In site, In(4) is bonded to one S(2), one S(6), two equivalent S(4), and two equivalent S(7) atoms to form InS6 octahedra that share corners with two equivalent In(1)S6 octahedra, corners with two equivalent In(2)S6 octahedra, corners with two equivalent Bi(1)S5 square pyramids,  a cornercorner with one In(3)S4 trigonal pyramid, edges with two equivalent In(4)S6 octahedra, and edges with three equivalent Bi(1)S5 square pyramids. The corner-sharing octahedral tilt angles range from 51-55°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent S(2) and three equivalent S(4) atoms to form distorted BiS5 square pyramids that share corners with two equivalent In(4)S6 octahedra, edges with three equivalent In(4)S6 octahedra, and edges with four equivalent Bi(1)S5 square pyramids. The corner-sharing octahedral tilt angles are 17°. In the second Bi site, Bi(2) is bonded to two equivalent S(9) and three equivalent S(5) atoms to form distorted BiS5 square pyramids that share corners with two equivalent In(2)S6 octahedra, edges with three equivalent In(2)S6 octahedra, and edges with four equivalent Bi(2)S5 square pyramids. The corner-sharing octahedral tilt angles are 20°. There are nine inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to three equivalent In(1) atoms. In the second S site, S(2) is bonded in a distorted T-shaped geometry to one In(4) and two equivalent Bi(1) atoms. In the third S site, S(3) is bonded in a trigonal non-coplanar geometry to one In(3) and two equivalent In(2) atoms. In the fourth S site, S(4) is bonded to two equivalent In(4) and three equivalent Bi(1) atoms to form distorted edge-sharing SIn2Bi3 square pyramids. In the fifth S site, S(5) is bonded to two equivalent In(2) and three equivalent Bi(2) atoms to form distorted edge-sharing SIn2Bi3 square pyramids. In the sixth S site, S(6) is bonded in a rectangular see-saw-like geometry to one In(3), one In(4), and two equivalent In(1) atoms. In the seventh S site, S(7) is bonded in a trigonal planar geometry to one In(2) and two equivalent In(4) atoms. In the eighth S site, S(8) is bonded in a distorted T-shaped geometry to one In(1) and two equivalent In(3) atoms. In the ninth S site, S(9) is bonded in a 3-coordinate geometry to one In(2) and two equivalent Bi(2) atoms.
In4Bi2S9 crystallizes in the monoclinic P2_1/m space group. There are four inequivalent In sites. In the first In site, In(1) is bonded to one S(8), two equivalent S(6), and three equivalent S(1) atoms to form InS6 octahedra that share corners with two equivalent In(4)S6 octahedra, edges with four equivalent In(1)S6 octahedra, and edges with two equivalent In(3)S4 trigonal pyramids. The corner-sharing octahedral tilt angles are 51°. The In(1)-S(8) bond length is 2.70 Å. Both In(1)-S(6) bond lengths are 2.68 Å. There is one shorter (2.58 Å) and two longer (2.64 Å) In(1)-S(1) bond lengths. In the second In site, In(2) is bonded to one S(7), one S(9), two equivalent S(3), and two equivalent S(5) atoms to form InS6 octahedra that share corners with two equivalent In(4)S6 octahedra, corners with two equivalent Bi(2)S5 square pyramids, corners with two equivalent In(3)S4 trigonal pyramids, edges with two equivalent In(2)S6 octahedra, and edges with three equivalent Bi(2)S5 square pyramids. The corner-sharing octahedral tilt angles are 55°. The In(2)-S(7) bond length is 2.52 Å. The In(2)-S(9) bond length is 2.61 Å. Both In(2)-S(3) bond lengths are 2.58 Å. Both In(2)-S(5) bond lengths are 2.82 Å. In the third In site, In(3) is bonded to one S(3), one S(6), and two equivalent S(8) atoms to form distorted InS4 trigonal pyramids that share  a cornercorner with one In(4)S6 octahedra, corners with two equivalent In(2)S6 octahedra, corners with two equivalent In(3)S4 trigonal pyramids, and edges with two equivalent In(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 66-70°. The In(3)-S(3) bond length is 2.44 Å. The In(3)-S(6) bond length is 2.56 Å. Both In(3)-S(8) bond lengths are 2.48 Å. In the fourth In site, In(4) is bonded to one S(2), one S(6), two equivalent S(4), and two equivalent S(7) atoms to form InS6 octahedra that share corners with two equivalent In(1)S6 octahedra, corners with two equivalent In(2)S6 octahedra, corners with two equivalent Bi(1)S5 square pyramids,  a cornercorner with one In(3)S4 trigonal pyramid, edges with two equivalent In(4)S6 octahedra, and edges with three equivalent Bi(1)S5 square pyramids. The corner-sharing octahedral tilt angles range from 51-55°. The In(4)-S(2) bond length is 2.63 Å. The In(4)-S(6) bond length is 2.60 Å. Both In(4)-S(4) bond lengths are 2.76 Å. Both In(4)-S(7) bond lengths are 2.54 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent S(2) and three equivalent S(4) atoms to form distorted BiS5 square pyramids that share corners with two equivalent In(4)S6 octahedra, edges with three equivalent In(4)S6 octahedra, and edges with four equivalent Bi(1)S5 square pyramids. The corner-sharing octahedral tilt angles are 17°. Both Bi(1)-S(2) bond lengths are 2.68 Å. There is one shorter (2.64 Å) and two longer (3.08 Å) Bi(1)-S(4) bond lengths. In the second Bi site, Bi(2) is bonded to two equivalent S(9) and three equivalent S(5) atoms to form distorted BiS5 square pyramids that share corners with two equivalent In(2)S6 octahedra, edges with three equivalent In(2)S6 octahedra, and edges with four equivalent Bi(2)S5 square pyramids. The corner-sharing octahedral tilt angles are 20°. Both Bi(2)-S(9) bond lengths are 2.70 Å. There is one shorter (2.58 Å) and two longer (3.00 Å) Bi(2)-S(5) bond lengths. There are nine inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to three equivalent In(1) atoms. In the second S site, S(2) is bonded in a distorted T-shaped geometry to one In(4) and two equivalent Bi(1) atoms. In the third S site, S(3) is bonded in a trigonal non-coplanar geometry to one In(3) and two equivalent In(2) atoms. In the fourth S site, S(4) is bonded to two equivalent In(4) and three equivalent Bi(1) atoms to form distorted edge-sharing SIn2Bi3 square pyramids. In the fifth S site, S(5) is bonded to two equivalent In(2) and three equivalent Bi(2) atoms to form distorted edge-sharing SIn2Bi3 square pyramids. In the sixth S site, S(6) is bonded in a rectangular see-saw-like geometry to one In(3), one In(4), and two equivalent In(1) atoms. In the seventh S site, S(7) is bonded in a trigonal planar geometry to one In(2) and two equivalent In(4) atoms. In the eighth S site, S(8) is bonded in a distorted T-shaped geometry to one In(1) and two equivalent In(3) atoms. In the ninth S site, S(9) is bonded in a 3-coordinate geometry to one In(2) and two equivalent Bi(2) atoms.