RbBi3S5 crystallizes in the orthorhombic Pnnm space group. Rb(1) is bonded in a 7-coordinate geometry to one S(3), two equivalent S(2), two equivalent S(4), and two equivalent S(6) atoms. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one S(1), one S(6), two equivalent S(4), and two equivalent S(5) atoms to form BiS6 octahedra that share  a cornercorner with one Bi(1)S6 octahedra, corners with four equivalent Bi(2)S5 square pyramids, edges with two equivalent Bi(1)S6 octahedra, edges with four equivalent Bi(3)S6 octahedra, and  an edgeedge with one Bi(2)S5 square pyramid. The corner-sharing octahedra are not tilted. In the second Bi site, Bi(2) is bonded to one S(3), two equivalent S(5), and two equivalent S(6) atoms to form distorted BiS5 square pyramids that share corners with four equivalent Bi(1)S6 octahedra,  an edgeedge with one Bi(1)S6 octahedra, edges with two equivalent Bi(3)S6 octahedra, and edges with two equivalent Bi(2)S5 square pyramids. The corner-sharing octahedral tilt angles range from 1-79°. In the third Bi site, Bi(3) is bonded to one S(4), one S(5), two equivalent S(1), and two equivalent S(3) atoms to form BiS6 octahedra that share corners with two equivalent Bi(3)S6 octahedra, edges with three equivalent Bi(3)S6 octahedra, edges with four equivalent Bi(1)S6 octahedra, and edges with two equivalent Bi(2)S5 square pyramids. The corner-sharing octahedra are not tilted. There are six inequivalent S sites. In the first S site, S(6) is bonded to two equivalent Rb(1), one Bi(1), and two equivalent Bi(2) atoms to form distorted SRb2Bi3 trigonal bipyramids that share  a cornercorner with one S(1)Bi6 octahedra, corners with four equivalent S(5)Bi5 square pyramids, corners with four equivalent S(4)Rb2Bi3 square pyramids,  an edgeedge with one S(5)Bi5 square pyramid,  an edgeedge with one S(4)Rb2Bi3 square pyramid, and edges with two equivalent S(6)Rb2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. In the second S site, S(1) is bonded to two equivalent Bi(1) and four equivalent Bi(3) atoms to form SBi6 octahedra that share corners with two equivalent S(6)Rb2Bi3 trigonal bipyramids, edges with two equivalent S(1)Bi6 octahedra, edges with four equivalent S(5)Bi5 square pyramids, and edges with four equivalent S(4)Rb2Bi3 square pyramids. In the third S site, S(2) is bonded in a square co-planar geometry to four equivalent Rb(1) atoms. In the fourth S site, S(3) is bonded in a 4-coordinate geometry to one Rb(1), one Bi(2), and two equivalent Bi(3) atoms. In the fifth S site, S(4) is bonded to two equivalent Rb(1), one Bi(3), and two equivalent Bi(1) atoms to form distorted SRb2Bi3 square pyramids that share corners with three equivalent S(5)Bi5 square pyramids, corners with four equivalent S(6)Rb2Bi3 trigonal bipyramids, edges with two equivalent S(1)Bi6 octahedra,  an edgeedge with one S(5)Bi5 square pyramid, edges with two equivalent S(4)Rb2Bi3 square pyramids, and  an edgeedge with one S(6)Rb2Bi3 trigonal bipyramid. In the sixth S site, S(5) is bonded to one Bi(3), two equivalent Bi(1), and two equivalent Bi(2) atoms to form distorted SBi5 square pyramids that share corners with three equivalent S(4)Rb2Bi3 square pyramids, corners with four equivalent S(6)Rb2Bi3 trigonal bipyramids, edges with two equivalent S(1)Bi6 octahedra,  an edgeedge with one S(4)Rb2Bi3 square pyramid, edges with two equivalent S(5)Bi5 square pyramids, and  an edgeedge with one S(6)Rb2Bi3 trigonal bipyramid.
RbBi3S5 crystallizes in the orthorhombic Pnnm space group. Rb(1) is bonded in a 7-coordinate geometry to one S(3), two equivalent S(2), two equivalent S(4), and two equivalent S(6) atoms. The Rb(1)-S(3) bond length is 3.55 Å. Both Rb(1)-S(2) bond lengths are 3.18 Å. Both Rb(1)-S(4) bond lengths are 3.70 Å. Both Rb(1)-S(6) bond lengths are 3.53 Å. There are three inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one S(1), one S(6), two equivalent S(4), and two equivalent S(5) atoms to form BiS6 octahedra that share  a cornercorner with one Bi(1)S6 octahedra, corners with four equivalent Bi(2)S5 square pyramids, edges with two equivalent Bi(1)S6 octahedra, edges with four equivalent Bi(3)S6 octahedra, and  an edgeedge with one Bi(2)S5 square pyramid. The corner-sharing octahedra are not tilted. The Bi(1)-S(1) bond length is 2.97 Å. The Bi(1)-S(6) bond length is 2.72 Å. Both Bi(1)-S(4) bond lengths are 2.76 Å. Both Bi(1)-S(5) bond lengths are 3.00 Å. In the second Bi site, Bi(2) is bonded to one S(3), two equivalent S(5), and two equivalent S(6) atoms to form distorted BiS5 square pyramids that share corners with four equivalent Bi(1)S6 octahedra,  an edgeedge with one Bi(1)S6 octahedra, edges with two equivalent Bi(3)S6 octahedra, and edges with two equivalent Bi(2)S5 square pyramids. The corner-sharing octahedral tilt angles range from 1-79°. The Bi(2)-S(3) bond length is 2.65 Å. Both Bi(2)-S(5) bond lengths are 3.00 Å. Both Bi(2)-S(6) bond lengths are 2.75 Å. In the third Bi site, Bi(3) is bonded to one S(4), one S(5), two equivalent S(1), and two equivalent S(3) atoms to form BiS6 octahedra that share corners with two equivalent Bi(3)S6 octahedra, edges with three equivalent Bi(3)S6 octahedra, edges with four equivalent Bi(1)S6 octahedra, and edges with two equivalent Bi(2)S5 square pyramids. The corner-sharing octahedra are not tilted. The Bi(3)-S(4) bond length is 3.02 Å. The Bi(3)-S(5) bond length is 2.78 Å. Both Bi(3)-S(1) bond lengths are 3.02 Å. Both Bi(3)-S(3) bond lengths are 2.78 Å. There are six inequivalent S sites. In the first S site, S(6) is bonded to two equivalent Rb(1), one Bi(1), and two equivalent Bi(2) atoms to form distorted SRb2Bi3 trigonal bipyramids that share  a cornercorner with one S(1)Bi6 octahedra, corners with four equivalent S(5)Bi5 square pyramids, corners with four equivalent S(4)Rb2Bi3 square pyramids,  an edgeedge with one S(5)Bi5 square pyramid,  an edgeedge with one S(4)Rb2Bi3 square pyramid, and edges with two equivalent S(6)Rb2Bi3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 3°. In the second S site, S(1) is bonded to two equivalent Bi(1) and four equivalent Bi(3) atoms to form SBi6 octahedra that share corners with two equivalent S(6)Rb2Bi3 trigonal bipyramids, edges with two equivalent S(1)Bi6 octahedra, edges with four equivalent S(5)Bi5 square pyramids, and edges with four equivalent S(4)Rb2Bi3 square pyramids. In the third S site, S(2) is bonded in a square co-planar geometry to four equivalent Rb(1) atoms. In the fourth S site, S(3) is bonded in a 4-coordinate geometry to one Rb(1), one Bi(2), and two equivalent Bi(3) atoms. In the fifth S site, S(4) is bonded to two equivalent Rb(1), one Bi(3), and two equivalent Bi(1) atoms to form distorted SRb2Bi3 square pyramids that share corners with three equivalent S(5)Bi5 square pyramids, corners with four equivalent S(6)Rb2Bi3 trigonal bipyramids, edges with two equivalent S(1)Bi6 octahedra,  an edgeedge with one S(5)Bi5 square pyramid, edges with two equivalent S(4)Rb2Bi3 square pyramids, and  an edgeedge with one S(6)Rb2Bi3 trigonal bipyramid. In the sixth S site, S(5) is bonded to one Bi(3), two equivalent Bi(1), and two equivalent Bi(2) atoms to form distorted SBi5 square pyramids that share corners with three equivalent S(4)Rb2Bi3 square pyramids, corners with four equivalent S(6)Rb2Bi3 trigonal bipyramids, edges with two equivalent S(1)Bi6 octahedra,  an edgeedge with one S(4)Rb2Bi3 square pyramid, edges with two equivalent S(5)Bi5 square pyramids, and  an edgeedge with one S(6)Rb2Bi3 trigonal bipyramid.