Rh8Bi8O27 crystallizes in the trigonal R3m space group. There are four inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(2), one O(9), two equivalent O(1), and two equivalent O(10) atoms to form RhO6 octahedra that share  a cornercorner with one Rh(2)O6 octahedra,  a cornercorner with one Rh(4)O6 octahedra, corners with four equivalent Rh(1)O6 octahedra, edges with two equivalent Bi(1)O7 hexagonal pyramids, and edges with two equivalent Bi(2)O7 hexagonal pyramids. The corner-sharing octahedral tilt angles range from 50-52°. In the second Rh site, Rh(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form RhO6 octahedra that share corners with three equivalent Rh(1)O6 octahedra, corners with three equivalent Rh(3)O6 octahedra, and edges with six equivalent Bi(2)O7 hexagonal pyramids. The corner-sharing octahedral tilt angles range from 50-52°. In the third Rh site, Rh(3) is bonded to one O(3), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form RhO6 octahedra that share  a cornercorner with one Rh(2)O6 octahedra,  a cornercorner with one Rh(4)O6 octahedra, corners with four equivalent Rh(3)O6 octahedra, and edges with two equivalent Bi(2)O7 hexagonal pyramids. The corner-sharing octahedral tilt angles range from 50-52°. In the fourth Rh site, Rh(4) is bonded to three equivalent O(7) and three equivalent O(9) atoms to form corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(11), three equivalent O(1), and three equivalent O(10) atoms to form distorted BiO7 hexagonal pyramids that share corners with three equivalent Bi(2)O7 hexagonal pyramids and edges with six equivalent Rh(1)O6 octahedra. In the second Bi site, Bi(2) is bonded to one O(1), one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form distorted BiO7 hexagonal pyramids that share  a cornercorner with one Bi(1)O7 hexagonal pyramid, corners with two equivalent Bi(2)O7 hexagonal pyramids, edges with two equivalent Bi(2)O7 hexagonal pyramids, edges with two equivalent Rh(1)O6 octahedra, edges with two equivalent Rh(2)O6 octahedra, and edges with two equivalent Rh(3)O6 octahedra. In the third Bi site, Bi(3) is bonded in a distorted body-centered cubic geometry to one O(6), one O(8), three equivalent O(4), and three equivalent O(5) atoms. In the fourth Bi site, Bi(4) is bonded in a distorted body-centered cubic geometry to one O(10), one O(11), one O(4), one O(8), two equivalent O(7), and two equivalent O(9) atoms. There are eleven inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Rh(1), one Bi(1), and one Bi(2) atom to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(5)Bi2Rh2 tetrahedra,  a cornercorner with one O(11)Bi4 tetrahedra,  a cornercorner with one O(6)Bi4 tetrahedra, corners with two equivalent O(3)Bi2Rh2 tetrahedra, corners with two equivalent O(9)Bi2Rh2 tetrahedra, corners with three equivalent O(10)Bi2Rh2 tetrahedra, corners with four equivalent O(1)Bi2Rh2 tetrahedra, edges with two equivalent O(10)Bi2Rh2 tetrahedra, and edges with two equivalent O(2)Bi2Rh2 tetrahedra. In the second O site, O(2) is bonded to one Rh(1), one Rh(2), and two equivalent Bi(2) atoms to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(9)Bi2Rh2 tetrahedra, corners with two equivalent O(10)Bi2Rh2 tetrahedra, corners with two equivalent O(5)Bi2Rh2 tetrahedra, corners with three equivalent O(3)Bi2Rh2 tetrahedra, corners with four equivalent O(2)Bi2Rh2 tetrahedra,  an edgeedge with one O(6)Bi4 tetrahedra, edges with two equivalent O(1)Bi2Rh2 tetrahedra, and edges with two equivalent O(3)Bi2Rh2 tetrahedra. In the third O site, O(3) is bonded to one Rh(2), one Rh(3), and two equivalent Bi(2) atoms to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(7)Bi2Rh2 tetrahedra, corners with two equivalent O(1)Bi2Rh2 tetrahedra, corners with two equivalent O(4)Bi2Rh2 tetrahedra, corners with two equivalent O(6)Bi4 tetrahedra, corners with three equivalent O(2)Bi2Rh2 tetrahedra, corners with four equivalent O(3)Bi2Rh2 tetrahedra, edges with two equivalent O(2)Bi2Rh2 tetrahedra, and edges with two equivalent O(5)Bi2Rh2 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Rh(3), one Bi(3), and one Bi(4) atom to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(10)Bi2Rh2 tetrahedra,  a cornercorner with one O(11)Bi4 tetrahedra,  a cornercorner with one O(6)Bi4 tetrahedra, corners with two equivalent O(3)Bi2Rh2 tetrahedra, corners with two equivalent O(9)Bi2Rh2 tetrahedra, corners with three equivalent O(5)Bi2Rh2 tetrahedra, corners with four equivalent O(4)Bi2Rh2 tetrahedra,  an edgeedge with one O(8)Bi4 tetrahedra, edges with two equivalent O(5)Bi2Rh2 tetrahedra, and edges with two equivalent O(7)Bi2Rh2 tetrahedra. In the fifth O site, O(5) is bonded to two equivalent Rh(3), one Bi(2), and one Bi(3) atom to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(1)Bi2Rh2 tetrahedra,  a cornercorner with one O(8)Bi4 tetrahedra, corners with two equivalent O(2)Bi2Rh2 tetrahedra, corners with two equivalent O(7)Bi2Rh2 tetrahedra, corners with three equivalent O(4)Bi2Rh2 tetrahedra, corners with four equivalent O(5)Bi2Rh2 tetrahedra,  an edgeedge with one O(6)Bi4 tetrahedra, edges with two equivalent O(3)Bi2Rh2 tetrahedra, and edges with two equivalent O(4)Bi2Rh2 tetrahedra. In the sixth O site, O(6) is bonded to one Bi(3) and three equivalent Bi(2) atoms to form OBi4 tetrahedra that share  a cornercorner with one O(8)Bi4 tetrahedra, corners with three equivalent O(1)Bi2Rh2 tetrahedra, corners with three equivalent O(4)Bi2Rh2 tetrahedra, corners with six equivalent O(3)Bi2Rh2 tetrahedra, edges with three equivalent O(2)Bi2Rh2 tetrahedra, and edges with three equivalent O(5)Bi2Rh2 tetrahedra. In the seventh O site, O(7) is bonded to one Rh(3), one Rh(4), and two equivalent Bi(4) atoms to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(3)Bi2Rh2 tetrahedra, corners with two equivalent O(10)Bi2Rh2 tetrahedra, corners with two equivalent O(5)Bi2Rh2 tetrahedra, corners with two equivalent O(8)Bi4 tetrahedra, corners with three equivalent O(9)Bi2Rh2 tetrahedra, corners with four equivalent O(7)Bi2Rh2 tetrahedra,  an edgeedge with one O(11)Bi4 tetrahedra, edges with two equivalent O(4)Bi2Rh2 tetrahedra, and edges with two equivalent O(9)Bi2Rh2 tetrahedra. In the eighth O site, O(8) is bonded to one Bi(3) and three equivalent Bi(4) atoms to form OBi4 tetrahedra that share  a cornercorner with one O(6)Bi4 tetrahedra, corners with three equivalent O(10)Bi2Rh2 tetrahedra, corners with three equivalent O(5)Bi2Rh2 tetrahedra, corners with three equivalent O(11)Bi4 tetrahedra, corners with six equivalent O(7)Bi2Rh2 tetrahedra, edges with three equivalent O(4)Bi2Rh2 tetrahedra, and edges with three equivalent O(9)Bi2Rh2 tetrahedra. In the ninth O site, O(9) is bonded to one Rh(1), one Rh(4), and two equivalent Bi(4) atoms to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(2)Bi2Rh2 tetrahedra, corners with two equivalent O(1)Bi2Rh2 tetrahedra, corners with two equivalent O(4)Bi2Rh2 tetrahedra, corners with two equivalent O(11)Bi4 tetrahedra, corners with three equivalent O(7)Bi2Rh2 tetrahedra, corners with four equivalent O(9)Bi2Rh2 tetrahedra,  an edgeedge with one O(8)Bi4 tetrahedra, edges with two equivalent O(10)Bi2Rh2 tetrahedra, and edges with two equivalent O(7)Bi2Rh2 tetrahedra. In the tenth O site, O(10) is bonded to two equivalent Rh(1), one Bi(1), and one Bi(4) atom to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(4)Bi2Rh2 tetrahedra,  a cornercorner with one O(8)Bi4 tetrahedra, corners with two equivalent O(2)Bi2Rh2 tetrahedra, corners with two equivalent O(7)Bi2Rh2 tetrahedra, corners with three equivalent O(1)Bi2Rh2 tetrahedra, corners with four equivalent O(10)Bi2Rh2 tetrahedra,  an edgeedge with one O(11)Bi4 tetrahedra, edges with two equivalent O(1)Bi2Rh2 tetrahedra, and edges with two equivalent O(9)Bi2Rh2 tetrahedra. In the eleventh O site, O(11) is bonded to one Bi(1) and three equivalent Bi(4) atoms to form OBi4 tetrahedra that share corners with three equivalent O(1)Bi2Rh2 tetrahedra, corners with three equivalent O(4)Bi2Rh2 tetrahedra, corners with three equivalent O(8)Bi4 tetrahedra, corners with six equivalent O(9)Bi2Rh2 tetrahedra, edges with three equivalent O(10)Bi2Rh2 tetrahedra, and edges with three equivalent O(7)Bi2Rh2 tetrahedra.
Rh8Bi8O27 crystallizes in the trigonal R3m space group. There are four inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(2), one O(9), two equivalent O(1), and two equivalent O(10) atoms to form RhO6 octahedra that share  a cornercorner with one Rh(2)O6 octahedra,  a cornercorner with one Rh(4)O6 octahedra, corners with four equivalent Rh(1)O6 octahedra, edges with two equivalent Bi(1)O7 hexagonal pyramids, and edges with two equivalent Bi(2)O7 hexagonal pyramids. The corner-sharing octahedral tilt angles range from 50-52°. The Rh(1)-O(2) bond length is 2.05 Å. The Rh(1)-O(9) bond length is 2.01 Å. Both Rh(1)-O(1) bond lengths are 2.02 Å. Both Rh(1)-O(10) bond lengths are 2.03 Å. In the second Rh site, Rh(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form RhO6 octahedra that share corners with three equivalent Rh(1)O6 octahedra, corners with three equivalent Rh(3)O6 octahedra, and edges with six equivalent Bi(2)O7 hexagonal pyramids. The corner-sharing octahedral tilt angles range from 50-52°. All Rh(2)-O(2) bond lengths are 2.06 Å. All Rh(2)-O(3) bond lengths are 2.00 Å. In the third Rh site, Rh(3) is bonded to one O(3), one O(7), two equivalent O(4), and two equivalent O(5) atoms to form RhO6 octahedra that share  a cornercorner with one Rh(2)O6 octahedra,  a cornercorner with one Rh(4)O6 octahedra, corners with four equivalent Rh(3)O6 octahedra, and edges with two equivalent Bi(2)O7 hexagonal pyramids. The corner-sharing octahedral tilt angles range from 50-52°. The Rh(3)-O(3) bond length is 2.01 Å. The Rh(3)-O(7) bond length is 2.03 Å. Both Rh(3)-O(4) bond lengths are 2.01 Å. Both Rh(3)-O(5) bond lengths are 2.05 Å. In the fourth Rh site, Rh(4) is bonded to three equivalent O(7) and three equivalent O(9) atoms to form corner-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. All Rh(4)-O(7) bond lengths are 2.02 Å. All Rh(4)-O(9) bond lengths are 2.03 Å. There are four inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to one O(11), three equivalent O(1), and three equivalent O(10) atoms to form distorted BiO7 hexagonal pyramids that share corners with three equivalent Bi(2)O7 hexagonal pyramids and edges with six equivalent Rh(1)O6 octahedra. The Bi(1)-O(11) bond length is 2.15 Å. All Bi(1)-O(1) bond lengths are 2.49 Å. All Bi(1)-O(10) bond lengths are 2.52 Å. In the second Bi site, Bi(2) is bonded to one O(1), one O(5), one O(6), two equivalent O(2), and two equivalent O(3) atoms to form distorted BiO7 hexagonal pyramids that share  a cornercorner with one Bi(1)O7 hexagonal pyramid, corners with two equivalent Bi(2)O7 hexagonal pyramids, edges with two equivalent Bi(2)O7 hexagonal pyramids, edges with two equivalent Rh(1)O6 octahedra, edges with two equivalent Rh(2)O6 octahedra, and edges with two equivalent Rh(3)O6 octahedra. The Bi(2)-O(1) bond length is 2.48 Å. The Bi(2)-O(5) bond length is 2.52 Å. The Bi(2)-O(6) bond length is 2.25 Å. Both Bi(2)-O(2) bond lengths are 2.48 Å. Both Bi(2)-O(3) bond lengths are 2.53 Å. In the third Bi site, Bi(3) is bonded in a distorted body-centered cubic geometry to one O(6), one O(8), three equivalent O(4), and three equivalent O(5) atoms. The Bi(3)-O(6) bond length is 2.42 Å. The Bi(3)-O(8) bond length is 2.24 Å. All Bi(3)-O(4) bond lengths are 2.53 Å. All Bi(3)-O(5) bond lengths are 2.50 Å. In the fourth Bi site, Bi(4) is bonded in a distorted body-centered cubic geometry to one O(10), one O(11), one O(4), one O(8), two equivalent O(7), and two equivalent O(9) atoms. The Bi(4)-O(10) bond length is 2.49 Å. The Bi(4)-O(11) bond length is 2.31 Å. The Bi(4)-O(4) bond length is 2.54 Å. The Bi(4)-O(8) bond length is 2.27 Å. Both Bi(4)-O(7) bond lengths are 2.53 Å. Both Bi(4)-O(9) bond lengths are 2.49 Å. There are eleven inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Rh(1), one Bi(1), and one Bi(2) atom to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(5)Bi2Rh2 tetrahedra,  a cornercorner with one O(11)Bi4 tetrahedra,  a cornercorner with one O(6)Bi4 tetrahedra, corners with two equivalent O(3)Bi2Rh2 tetrahedra, corners with two equivalent O(9)Bi2Rh2 tetrahedra, corners with three equivalent O(10)Bi2Rh2 tetrahedra, corners with four equivalent O(1)Bi2Rh2 tetrahedra, edges with two equivalent O(10)Bi2Rh2 tetrahedra, and edges with two equivalent O(2)Bi2Rh2 tetrahedra. In the second O site, O(2) is bonded to one Rh(1), one Rh(2), and two equivalent Bi(2) atoms to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(9)Bi2Rh2 tetrahedra, corners with two equivalent O(10)Bi2Rh2 tetrahedra, corners with two equivalent O(5)Bi2Rh2 tetrahedra, corners with three equivalent O(3)Bi2Rh2 tetrahedra, corners with four equivalent O(2)Bi2Rh2 tetrahedra,  an edgeedge with one O(6)Bi4 tetrahedra, edges with two equivalent O(1)Bi2Rh2 tetrahedra, and edges with two equivalent O(3)Bi2Rh2 tetrahedra. In the third O site, O(3) is bonded to one Rh(2), one Rh(3), and two equivalent Bi(2) atoms to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(7)Bi2Rh2 tetrahedra, corners with two equivalent O(1)Bi2Rh2 tetrahedra, corners with two equivalent O(4)Bi2Rh2 tetrahedra, corners with two equivalent O(6)Bi4 tetrahedra, corners with three equivalent O(2)Bi2Rh2 tetrahedra, corners with four equivalent O(3)Bi2Rh2 tetrahedra, edges with two equivalent O(2)Bi2Rh2 tetrahedra, and edges with two equivalent O(5)Bi2Rh2 tetrahedra. In the fourth O site, O(4) is bonded to two equivalent Rh(3), one Bi(3), and one Bi(4) atom to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(10)Bi2Rh2 tetrahedra,  a cornercorner with one O(11)Bi4 tetrahedra,  a cornercorner with one O(6)Bi4 tetrahedra, corners with two equivalent O(3)Bi2Rh2 tetrahedra, corners with two equivalent O(9)Bi2Rh2 tetrahedra, corners with three equivalent O(5)Bi2Rh2 tetrahedra, corners with four equivalent O(4)Bi2Rh2 tetrahedra,  an edgeedge with one O(8)Bi4 tetrahedra, edges with two equivalent O(5)Bi2Rh2 tetrahedra, and edges with two equivalent O(7)Bi2Rh2 tetrahedra. In the fifth O site, O(5) is bonded to two equivalent Rh(3), one Bi(2), and one Bi(3) atom to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(1)Bi2Rh2 tetrahedra,  a cornercorner with one O(8)Bi4 tetrahedra, corners with two equivalent O(2)Bi2Rh2 tetrahedra, corners with two equivalent O(7)Bi2Rh2 tetrahedra, corners with three equivalent O(4)Bi2Rh2 tetrahedra, corners with four equivalent O(5)Bi2Rh2 tetrahedra,  an edgeedge with one O(6)Bi4 tetrahedra, edges with two equivalent O(3)Bi2Rh2 tetrahedra, and edges with two equivalent O(4)Bi2Rh2 tetrahedra. In the sixth O site, O(6) is bonded to one Bi(3) and three equivalent Bi(2) atoms to form OBi4 tetrahedra that share  a cornercorner with one O(8)Bi4 tetrahedra, corners with three equivalent O(1)Bi2Rh2 tetrahedra, corners with three equivalent O(4)Bi2Rh2 tetrahedra, corners with six equivalent O(3)Bi2Rh2 tetrahedra, edges with three equivalent O(2)Bi2Rh2 tetrahedra, and edges with three equivalent O(5)Bi2Rh2 tetrahedra. In the seventh O site, O(7) is bonded to one Rh(3), one Rh(4), and two equivalent Bi(4) atoms to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(3)Bi2Rh2 tetrahedra, corners with two equivalent O(10)Bi2Rh2 tetrahedra, corners with two equivalent O(5)Bi2Rh2 tetrahedra, corners with two equivalent O(8)Bi4 tetrahedra, corners with three equivalent O(9)Bi2Rh2 tetrahedra, corners with four equivalent O(7)Bi2Rh2 tetrahedra,  an edgeedge with one O(11)Bi4 tetrahedra, edges with two equivalent O(4)Bi2Rh2 tetrahedra, and edges with two equivalent O(9)Bi2Rh2 tetrahedra. In the eighth O site, O(8) is bonded to one Bi(3) and three equivalent Bi(4) atoms to form OBi4 tetrahedra that share  a cornercorner with one O(6)Bi4 tetrahedra, corners with three equivalent O(10)Bi2Rh2 tetrahedra, corners with three equivalent O(5)Bi2Rh2 tetrahedra, corners with three equivalent O(11)Bi4 tetrahedra, corners with six equivalent O(7)Bi2Rh2 tetrahedra, edges with three equivalent O(4)Bi2Rh2 tetrahedra, and edges with three equivalent O(9)Bi2Rh2 tetrahedra. In the ninth O site, O(9) is bonded to one Rh(1), one Rh(4), and two equivalent Bi(4) atoms to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(2)Bi2Rh2 tetrahedra, corners with two equivalent O(1)Bi2Rh2 tetrahedra, corners with two equivalent O(4)Bi2Rh2 tetrahedra, corners with two equivalent O(11)Bi4 tetrahedra, corners with three equivalent O(7)Bi2Rh2 tetrahedra, corners with four equivalent O(9)Bi2Rh2 tetrahedra,  an edgeedge with one O(8)Bi4 tetrahedra, edges with two equivalent O(10)Bi2Rh2 tetrahedra, and edges with two equivalent O(7)Bi2Rh2 tetrahedra. In the tenth O site, O(10) is bonded to two equivalent Rh(1), one Bi(1), and one Bi(4) atom to form distorted OBi2Rh2 tetrahedra that share  a cornercorner with one O(4)Bi2Rh2 tetrahedra,  a cornercorner with one O(8)Bi4 tetrahedra, corners with two equivalent O(2)Bi2Rh2 tetrahedra, corners with two equivalent O(7)Bi2Rh2 tetrahedra, corners with three equivalent O(1)Bi2Rh2 tetrahedra, corners with four equivalent O(10)Bi2Rh2 tetrahedra,  an edgeedge with one O(11)Bi4 tetrahedra, edges with two equivalent O(1)Bi2Rh2 tetrahedra, and edges with two equivalent O(9)Bi2Rh2 tetrahedra. In the eleventh O site, O(11) is bonded to one Bi(1) and three equivalent Bi(4) atoms to form OBi4 tetrahedra that share corners with three equivalent O(1)Bi2Rh2 tetrahedra, corners with three equivalent O(4)Bi2Rh2 tetrahedra, corners with three equivalent O(8)Bi4 tetrahedra, corners with six equivalent O(9)Bi2Rh2 tetrahedra, edges with three equivalent O(10)Bi2Rh2 tetrahedra, and edges with three equivalent O(7)Bi2Rh2 tetrahedra.