PbBi4S7 crystallizes in the monoclinic Cm space group. Pb(1) is bonded in a 4-coordinate geometry to one S(5), one S(7), and two equivalent S(4) atoms. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one S(2), one S(3), two equivalent S(1), and two equivalent S(7) atoms to form BiS6 octahedra that share  a cornercorner with one Bi(3)S6 octahedra, corners with two equivalent Bi(2)S6 octahedra, corners with two equivalent Bi(4)S5 square pyramids, edges with two equivalent Bi(1)S6 octahedra, and edges with three equivalent Bi(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 17-62°. In the second Bi site, Bi(2) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(7) atoms to form a mixture of corner and edge-sharing BiS6 octahedra. The corner-sharing octahedral tilt angles range from 17-40°. In the third Bi site, Bi(3) is bonded to one S(3), one S(4), two equivalent S(5), and two equivalent S(6) atoms to form BiS6 octahedra that share  a cornercorner with one Bi(1)S6 octahedra,  a cornercorner with one Bi(2)S6 octahedra, corners with two equivalent Bi(4)S5 square pyramids, edges with two equivalent Bi(3)S6 octahedra, and edges with three equivalent Bi(4)S5 square pyramids. The corner-sharing octahedral tilt angles range from 40-62°. In the fourth Bi site, Bi(4) is bonded to one S(6), two equivalent S(3), and two equivalent S(5) atoms to form BiS5 square pyramids that share corners with two equivalent Bi(1)S6 octahedra, corners with two equivalent Bi(3)S6 octahedra, edges with three equivalent Bi(3)S6 octahedra, and edges with two equivalent Bi(4)S5 square pyramids. The corner-sharing octahedral tilt angles range from 21-55°. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to one Bi(2) and two equivalent Bi(1) atoms. In the second S site, S(2) is bonded in a distorted T-shaped geometry to one Bi(1) and two equivalent Bi(2) atoms. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Bi(1), one Bi(3), and two equivalent Bi(4) atoms. In the fourth S site, S(4) is bonded to two equivalent Pb(1), one Bi(2), and one Bi(3) atom to form distorted SBi2Pb2 trigonal pyramids that share corners with two equivalent S(4)Bi2Pb2 trigonal pyramids and edges with two equivalent S(5)Bi4Pb trigonal bipyramids. In the fifth S site, S(5) is bonded to one Pb(1), two equivalent Bi(3), and two equivalent Bi(4) atoms to form distorted SBi4Pb trigonal bipyramids that share edges with two equivalent S(5)Bi4Pb trigonal bipyramids and edges with two equivalent S(4)Bi2Pb2 trigonal pyramids. In the sixth S site, S(6) is bonded in a distorted T-shaped geometry to one Bi(4) and two equivalent Bi(3) atoms. In the seventh S site, S(7) is bonded in a 5-coordinate geometry to one Pb(1), two equivalent Bi(1), and two equivalent Bi(2) atoms.
PbBi4S7 crystallizes in the monoclinic Cm space group. Pb(1) is bonded in a 4-coordinate geometry to one S(5), one S(7), and two equivalent S(4) atoms. The Pb(1)-S(5) bond length is 3.02 Å. The Pb(1)-S(7) bond length is 3.19 Å. Both Pb(1)-S(4) bond lengths are 2.78 Å. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one S(2), one S(3), two equivalent S(1), and two equivalent S(7) atoms to form BiS6 octahedra that share  a cornercorner with one Bi(3)S6 octahedra, corners with two equivalent Bi(2)S6 octahedra, corners with two equivalent Bi(4)S5 square pyramids, edges with two equivalent Bi(1)S6 octahedra, and edges with three equivalent Bi(2)S6 octahedra. The corner-sharing octahedral tilt angles range from 17-62°. The Bi(1)-S(2) bond length is 2.70 Å. The Bi(1)-S(3) bond length is 3.02 Å. Both Bi(1)-S(1) bond lengths are 2.78 Å. Both Bi(1)-S(7) bond lengths are 2.87 Å. In the second Bi site, Bi(2) is bonded to one S(1), one S(4), two equivalent S(2), and two equivalent S(7) atoms to form a mixture of corner and edge-sharing BiS6 octahedra. The corner-sharing octahedral tilt angles range from 17-40°. The Bi(2)-S(1) bond length is 2.82 Å. The Bi(2)-S(4) bond length is 2.78 Å. Both Bi(2)-S(2) bond lengths are 2.77 Å. Both Bi(2)-S(7) bond lengths are 2.88 Å. In the third Bi site, Bi(3) is bonded to one S(3), one S(4), two equivalent S(5), and two equivalent S(6) atoms to form BiS6 octahedra that share  a cornercorner with one Bi(1)S6 octahedra,  a cornercorner with one Bi(2)S6 octahedra, corners with two equivalent Bi(4)S5 square pyramids, edges with two equivalent Bi(3)S6 octahedra, and edges with three equivalent Bi(4)S5 square pyramids. The corner-sharing octahedral tilt angles range from 40-62°. The Bi(3)-S(3) bond length is 2.83 Å. The Bi(3)-S(4) bond length is 2.74 Å. Both Bi(3)-S(5) bond lengths are 2.88 Å. Both Bi(3)-S(6) bond lengths are 2.79 Å. In the fourth Bi site, Bi(4) is bonded to one S(6), two equivalent S(3), and two equivalent S(5) atoms to form BiS5 square pyramids that share corners with two equivalent Bi(1)S6 octahedra, corners with two equivalent Bi(3)S6 octahedra, edges with three equivalent Bi(3)S6 octahedra, and edges with two equivalent Bi(4)S5 square pyramids. The corner-sharing octahedral tilt angles range from 21-55°. The Bi(4)-S(6) bond length is 2.66 Å. Both Bi(4)-S(3) bond lengths are 2.75 Å. Both Bi(4)-S(5) bond lengths are 2.95 Å. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to one Bi(2) and two equivalent Bi(1) atoms. In the second S site, S(2) is bonded in a distorted T-shaped geometry to one Bi(1) and two equivalent Bi(2) atoms. In the third S site, S(3) is bonded in a rectangular see-saw-like geometry to one Bi(1), one Bi(3), and two equivalent Bi(4) atoms. In the fourth S site, S(4) is bonded to two equivalent Pb(1), one Bi(2), and one Bi(3) atom to form distorted SBi2Pb2 trigonal pyramids that share corners with two equivalent S(4)Bi2Pb2 trigonal pyramids and edges with two equivalent S(5)Bi4Pb trigonal bipyramids. In the fifth S site, S(5) is bonded to one Pb(1), two equivalent Bi(3), and two equivalent Bi(4) atoms to form distorted SBi4Pb trigonal bipyramids that share edges with two equivalent S(5)Bi4Pb trigonal bipyramids and edges with two equivalent S(4)Bi2Pb2 trigonal pyramids. In the sixth S site, S(6) is bonded in a distorted T-shaped geometry to one Bi(4) and two equivalent Bi(3) atoms. In the seventh S site, S(7) is bonded in a 5-coordinate geometry to one Pb(1), two equivalent Bi(1), and two equivalent Bi(2) atoms.