Ag3Bi7S12 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ag sites. In the first Ag site, Ag(1) is bonded to two equivalent S(3) and four equivalent S(6) atoms to form AgS6 octahedra that share corners with two equivalent Bi(4)S6 octahedra, corners with four equivalent Bi(3)S5 square pyramids, edges with two equivalent Ag(1)S6 octahedra, and edges with six equivalent Bi(3)S5 square pyramids. The corner-sharing octahedral tilt angles are 54°. In the second Ag site, Ag(2) is bonded to one S(2), two equivalent S(5), and three equivalent S(4) atoms to form AgS6 octahedra that share corners with two equivalent Bi(2)S6 octahedra, corners with three equivalent Bi(1)S6 octahedra, edges with two equivalent Bi(4)S6 octahedra, edges with three equivalent Bi(1)S6 octahedra, edges with three equivalent Bi(2)S6 octahedra, and edges with four equivalent Ag(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(5) atoms to form BiS6 octahedra that share corners with two equivalent Bi(4)S6 octahedra, corners with three equivalent Ag(2)S6 octahedra, edges with two equivalent Bi(1)S6 octahedra, edges with two equivalent Bi(2)S6 octahedra, edges with three equivalent Ag(2)S6 octahedra, and edges with three equivalent Bi(4)S6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. In the second Bi site, Bi(2) is bonded to two equivalent S(5) and four equivalent S(4) atoms to form BiS6 octahedra that share corners with two equivalent Bi(4)S6 octahedra, corners with four equivalent Ag(2)S6 octahedra, edges with two equivalent Bi(2)S6 octahedra, edges with four equivalent Bi(1)S6 octahedra, and edges with six equivalent Ag(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. In the third Bi site, Bi(3) is bonded to two equivalent S(3) and three equivalent S(6) atoms to form BiS5 square pyramids that share corners with two equivalent Ag(1)S6 octahedra, corners with two equivalent Bi(4)S6 octahedra, edges with three equivalent Ag(1)S6 octahedra, and edges with four equivalent Bi(3)S5 square pyramids. The corner-sharing octahedral tilt angles range from 14-65°. In the fourth Bi site, Bi(4) is bonded to one S(3), one S(5), two equivalent S(1), and two equivalent S(2) atoms to form BiS6 octahedra that share  a cornercorner with one Ag(1)S6 octahedra,  a cornercorner with one Bi(2)S6 octahedra, corners with two equivalent Bi(1)S6 octahedra, corners with two equivalent Bi(3)S5 square pyramids, edges with two equivalent Ag(2)S6 octahedra, edges with two equivalent Bi(4)S6 octahedra, and edges with three equivalent Bi(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 4-54°. There are six inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to one Bi(1) and two equivalent Bi(4) atoms. In the second S site, S(2) is bonded to one Ag(2), two equivalent Bi(1), and two equivalent Bi(4) atoms to form SAgBi4 square pyramids that share  a cornercorner with one S(4)Ag3Bi3 octahedra, corners with two equivalent S(5)Ag2Bi4 octahedra, corners with two equivalent S(3)AgBi3 tetrahedra, edges with two equivalent S(4)Ag3Bi3 octahedra, edges with three equivalent S(5)Ag2Bi4 octahedra, and edges with two equivalent S(2)AgBi4 square pyramids. The corner-sharing octahedral tilt angles range from 3-5°. In the third S site, S(3) is bonded to one Ag(1), one Bi(4), and two equivalent Bi(3) atoms to form distorted SAgBi3 tetrahedra that share  a cornercorner with one S(5)Ag2Bi4 octahedra, corners with two equivalent S(2)AgBi4 square pyramids, corners with four equivalent S(6)Ag2Bi3 square pyramids, corners with three equivalent S(3)AgBi3 tetrahedra, and edges with three equivalent S(6)Ag2Bi3 square pyramids. The corner-sharing octahedra are not tilted. In the fourth S site, S(4) is bonded to three equivalent Ag(2), one Bi(1), and two equivalent Bi(2) atoms to form SAg3Bi3 octahedra that share corners with two equivalent S(5)Ag2Bi4 octahedra, corners with two equivalent S(4)Ag3Bi3 octahedra,  a cornercorner with one S(2)AgBi4 square pyramid, edges with five equivalent S(5)Ag2Bi4 octahedra, edges with five equivalent S(4)Ag3Bi3 octahedra, and edges with two equivalent S(2)AgBi4 square pyramids. The corner-sharing octahedral tilt angles range from 0-7°. In the fifth S site, S(5) is bonded to two equivalent Ag(2), one Bi(2), one Bi(4), and two equivalent Bi(1) atoms to form SAg2Bi4 octahedra that share  a cornercorner with one S(5)Ag2Bi4 octahedra, corners with two equivalent S(4)Ag3Bi3 octahedra, corners with two equivalent S(2)AgBi4 square pyramids,  a cornercorner with one S(3)AgBi3 tetrahedra, edges with two equivalent S(5)Ag2Bi4 octahedra, edges with five equivalent S(4)Ag3Bi3 octahedra, and edges with three equivalent S(2)AgBi4 square pyramids. The corner-sharing octahedral tilt angles range from 0-7°. In the sixth S site, S(6) is bonded to two equivalent Ag(1) and three equivalent Bi(3) atoms to form SAg2Bi3 square pyramids that share corners with two equivalent S(6)Ag2Bi3 square pyramids, corners with four equivalent S(3)AgBi3 tetrahedra, edges with five equivalent S(6)Ag2Bi3 square pyramids, and edges with three equivalent S(3)AgBi3 tetrahedra.
Ag3Bi7S12 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ag sites. In the first Ag site, Ag(1) is bonded to two equivalent S(3) and four equivalent S(6) atoms to form AgS6 octahedra that share corners with two equivalent Bi(4)S6 octahedra, corners with four equivalent Bi(3)S5 square pyramids, edges with two equivalent Ag(1)S6 octahedra, and edges with six equivalent Bi(3)S5 square pyramids. The corner-sharing octahedral tilt angles are 54°. Both Ag(1)-S(3) bond lengths are 2.54 Å. All Ag(1)-S(6) bond lengths are 2.90 Å. In the second Ag site, Ag(2) is bonded to one S(2), two equivalent S(5), and three equivalent S(4) atoms to form AgS6 octahedra that share corners with two equivalent Bi(2)S6 octahedra, corners with three equivalent Bi(1)S6 octahedra, edges with two equivalent Bi(4)S6 octahedra, edges with three equivalent Bi(1)S6 octahedra, edges with three equivalent Bi(2)S6 octahedra, and edges with four equivalent Ag(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. The Ag(2)-S(2) bond length is 2.63 Å. Both Ag(2)-S(5) bond lengths are 3.05 Å. There is one shorter (2.72 Å) and two longer (2.89 Å) Ag(2)-S(4) bond lengths. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(5) atoms to form BiS6 octahedra that share corners with two equivalent Bi(4)S6 octahedra, corners with three equivalent Ag(2)S6 octahedra, edges with two equivalent Bi(1)S6 octahedra, edges with two equivalent Bi(2)S6 octahedra, edges with three equivalent Ag(2)S6 octahedra, and edges with three equivalent Bi(4)S6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. The Bi(1)-S(1) bond length is 2.77 Å. The Bi(1)-S(4) bond length is 2.98 Å. Both Bi(1)-S(2) bond lengths are 2.89 Å. Both Bi(1)-S(5) bond lengths are 2.83 Å. In the second Bi site, Bi(2) is bonded to two equivalent S(5) and four equivalent S(4) atoms to form BiS6 octahedra that share corners with two equivalent Bi(4)S6 octahedra, corners with four equivalent Ag(2)S6 octahedra, edges with two equivalent Bi(2)S6 octahedra, edges with four equivalent Bi(1)S6 octahedra, and edges with six equivalent Ag(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 4-8°. Both Bi(2)-S(5) bond lengths are 2.81 Å. All Bi(2)-S(4) bond lengths are 2.87 Å. In the third Bi site, Bi(3) is bonded to two equivalent S(3) and three equivalent S(6) atoms to form BiS5 square pyramids that share corners with two equivalent Ag(1)S6 octahedra, corners with two equivalent Bi(4)S6 octahedra, edges with three equivalent Ag(1)S6 octahedra, and edges with four equivalent Bi(3)S5 square pyramids. The corner-sharing octahedral tilt angles range from 14-65°. Both Bi(3)-S(3) bond lengths are 2.84 Å. There is one shorter (2.63 Å) and two longer (2.85 Å) Bi(3)-S(6) bond lengths. In the fourth Bi site, Bi(4) is bonded to one S(3), one S(5), two equivalent S(1), and two equivalent S(2) atoms to form BiS6 octahedra that share  a cornercorner with one Ag(1)S6 octahedra,  a cornercorner with one Bi(2)S6 octahedra, corners with two equivalent Bi(1)S6 octahedra, corners with two equivalent Bi(3)S5 square pyramids, edges with two equivalent Ag(2)S6 octahedra, edges with two equivalent Bi(4)S6 octahedra, and edges with three equivalent Bi(1)S6 octahedra. The corner-sharing octahedral tilt angles range from 4-54°. The Bi(4)-S(3) bond length is 2.66 Å. The Bi(4)-S(5) bond length is 3.00 Å. Both Bi(4)-S(1) bond lengths are 2.80 Å. Both Bi(4)-S(2) bond lengths are 2.94 Å. There are six inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to one Bi(1) and two equivalent Bi(4) atoms. In the second S site, S(2) is bonded to one Ag(2), two equivalent Bi(1), and two equivalent Bi(4) atoms to form SAgBi4 square pyramids that share  a cornercorner with one S(4)Ag3Bi3 octahedra, corners with two equivalent S(5)Ag2Bi4 octahedra, corners with two equivalent S(3)AgBi3 tetrahedra, edges with two equivalent S(4)Ag3Bi3 octahedra, edges with three equivalent S(5)Ag2Bi4 octahedra, and edges with two equivalent S(2)AgBi4 square pyramids. The corner-sharing octahedral tilt angles range from 3-5°. In the third S site, S(3) is bonded to one Ag(1), one Bi(4), and two equivalent Bi(3) atoms to form distorted SAgBi3 tetrahedra that share  a cornercorner with one S(5)Ag2Bi4 octahedra, corners with two equivalent S(2)AgBi4 square pyramids, corners with four equivalent S(6)Ag2Bi3 square pyramids, corners with three equivalent S(3)AgBi3 tetrahedra, and edges with three equivalent S(6)Ag2Bi3 square pyramids. The corner-sharing octahedra are not tilted. In the fourth S site, S(4) is bonded to three equivalent Ag(2), one Bi(1), and two equivalent Bi(2) atoms to form SAg3Bi3 octahedra that share corners with two equivalent S(5)Ag2Bi4 octahedra, corners with two equivalent S(4)Ag3Bi3 octahedra,  a cornercorner with one S(2)AgBi4 square pyramid, edges with five equivalent S(5)Ag2Bi4 octahedra, edges with five equivalent S(4)Ag3Bi3 octahedra, and edges with two equivalent S(2)AgBi4 square pyramids. The corner-sharing octahedral tilt angles range from 0-7°. In the fifth S site, S(5) is bonded to two equivalent Ag(2), one Bi(2), one Bi(4), and two equivalent Bi(1) atoms to form SAg2Bi4 octahedra that share  a cornercorner with one S(5)Ag2Bi4 octahedra, corners with two equivalent S(4)Ag3Bi3 octahedra, corners with two equivalent S(2)AgBi4 square pyramids,  a cornercorner with one S(3)AgBi3 tetrahedra, edges with two equivalent S(5)Ag2Bi4 octahedra, edges with five equivalent S(4)Ag3Bi3 octahedra, and edges with three equivalent S(2)AgBi4 square pyramids. The corner-sharing octahedral tilt angles range from 0-7°. In the sixth S site, S(6) is bonded to two equivalent Ag(1) and three equivalent Bi(3) atoms to form SAg2Bi3 square pyramids that share corners with two equivalent S(6)Ag2Bi3 square pyramids, corners with four equivalent S(3)AgBi3 tetrahedra, edges with five equivalent S(6)Ag2Bi3 square pyramids, and edges with three equivalent S(3)AgBi3 tetrahedra.