MgSb2(RhO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with two equivalent Rh(2)O6 octahedra, edges with two equivalent Rh(1)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and  a faceface with one Rh(2)O6 octahedra. The corner-sharing octahedral tilt angles are 49°. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form RhO6 octahedra that share corners with four equivalent Rh(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-54°. In the second Rh site, Rh(2) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form distorted RhO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Rh(1)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form SbO6 octahedra that share corners with four equivalent Rh(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Rh(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. In the second Sb site, Sb(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Rh(2), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded to one Mg(1), one Rh(1), one Rh(2), and one Sb(2) atom to form distorted OMgSbRh2 trigonal pyramids that share  a cornercorner with one O(4)MgSb2Rh trigonal pyramid,  a cornercorner with one O(5)MgSbRh2 trigonal pyramid,  an edgeedge with one O(4)MgSb2Rh trigonal pyramid, and  an edgeedge with one O(5)MgSbRh2 trigonal pyramid. In the third O site, O(3) is bonded in a trigonal planar geometry to one Rh(1), one Rh(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Rh(1), one Sb(1), and one Sb(2) atom to form a mixture of distorted corner and edge-sharing OMgSb2Rh trigonal pyramids. In the fifth O site, O(5) is bonded to one Mg(1), one Rh(1), one Rh(2), and one Sb(1) atom to form distorted OMgSbRh2 trigonal pyramids that share  a cornercorner with one O(2)MgSbRh2 trigonal pyramid, corners with three equivalent O(4)MgSb2Rh trigonal pyramids, and  an edgeedge with one O(2)MgSbRh2 trigonal pyramid. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Rh(1), one Sb(1), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Rh(1), one Rh(2), and one Sb(2) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Rh(2), one Sb(1), and one Sb(2) atom.
MgSb2(RhO4)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom to form MgO6 octahedra that share corners with two equivalent Rh(2)O6 octahedra, edges with two equivalent Rh(1)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and  a faceface with one Rh(2)O6 octahedra. The corner-sharing octahedral tilt angles are 49°. The Mg(1)-O(1) bond length is 2.09 Å. The Mg(1)-O(2) bond length is 2.07 Å. The Mg(1)-O(4) bond length is 2.01 Å. The Mg(1)-O(5) bond length is 2.01 Å. The Mg(1)-O(7) bond length is 2.14 Å. The Mg(1)-O(8) bond length is 2.12 Å. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form RhO6 octahedra that share corners with four equivalent Rh(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-54°. The Rh(1)-O(2) bond length is 2.16 Å. The Rh(1)-O(3) bond length is 2.11 Å. The Rh(1)-O(4) bond length is 2.05 Å. The Rh(1)-O(5) bond length is 2.15 Å. The Rh(1)-O(6) bond length is 2.04 Å. The Rh(1)-O(7) bond length is 2.06 Å. In the second Rh site, Rh(2) is bonded to one O(1), one O(2), one O(3), one O(5), one O(7), and one O(8) atom to form distorted RhO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with four equivalent Rh(1)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. The Rh(2)-O(1) bond length is 2.23 Å. The Rh(2)-O(2) bond length is 2.11 Å. The Rh(2)-O(3) bond length is 2.07 Å. The Rh(2)-O(5) bond length is 2.38 Å. The Rh(2)-O(7) bond length is 2.10 Å. The Rh(2)-O(8) bond length is 2.13 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(8) atom to form SbO6 octahedra that share corners with four equivalent Rh(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Rh(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. The Sb(1)-O(1) bond length is 2.11 Å. The Sb(1)-O(3) bond length is 2.04 Å. The Sb(1)-O(4) bond length is 2.03 Å. The Sb(1)-O(5) bond length is 2.08 Å. The Sb(1)-O(6) bond length is 2.06 Å. The Sb(1)-O(8) bond length is 2.02 Å. In the second Sb site, Sb(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), and one O(8) atom. The Sb(2)-O(1) bond length is 2.15 Å. The Sb(2)-O(2) bond length is 2.08 Å. The Sb(2)-O(4) bond length is 2.53 Å. The Sb(2)-O(6) bond length is 2.05 Å. The Sb(2)-O(7) bond length is 2.34 Å. The Sb(2)-O(8) bond length is 2.50 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one Rh(2), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded to one Mg(1), one Rh(1), one Rh(2), and one Sb(2) atom to form distorted OMgSbRh2 trigonal pyramids that share  a cornercorner with one O(4)MgSb2Rh trigonal pyramid,  a cornercorner with one O(5)MgSbRh2 trigonal pyramid,  an edgeedge with one O(4)MgSb2Rh trigonal pyramid, and  an edgeedge with one O(5)MgSbRh2 trigonal pyramid. In the third O site, O(3) is bonded in a trigonal planar geometry to one Rh(1), one Rh(2), and one Sb(1) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Rh(1), one Sb(1), and one Sb(2) atom to form a mixture of distorted corner and edge-sharing OMgSb2Rh trigonal pyramids. In the fifth O site, O(5) is bonded to one Mg(1), one Rh(1), one Rh(2), and one Sb(1) atom to form distorted OMgSbRh2 trigonal pyramids that share  a cornercorner with one O(2)MgSbRh2 trigonal pyramid, corners with three equivalent O(4)MgSb2Rh trigonal pyramids, and  an edgeedge with one O(2)MgSbRh2 trigonal pyramid. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Rh(1), one Sb(1), and one Sb(2) atom. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Rh(1), one Rh(2), and one Sb(2) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Rh(2), one Sb(1), and one Sb(2) atom.