MgSb2(RhO4)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), and two equivalent O(1) atoms. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form RhO6 octahedra that share corners with four equivalent Rh(2)O6 octahedra and corners with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-57°. In the second Rh site, Rh(2) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form RhO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with four equivalent Rh(1)O6 octahedra, and  a faceface with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-56°. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Rh(2)O6 octahedra, corners with four equivalent Rh(1)O6 octahedra, and  a faceface with one Rh(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. In the second Sb site, Sb(2) is bonded in a distorted see-saw-like geometry to one O(4), one O(6), and two equivalent O(1) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate 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 in a 3-coordinate geometry to one Rh(1), one Rh(2), and one Sb(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Rh(1), and one Rh(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Mg(1), one Rh(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Rh(1), one Rh(2), and one Sb(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Rh(1), one Sb(1), and one Sb(2) atom.
MgSb2(RhO4)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(3), one O(4), and two equivalent O(1) atoms. The Mg(1)-O(3) bond length is 1.95 Å. The Mg(1)-O(4) bond length is 2.00 Å. Both Mg(1)-O(1) bond lengths are 2.13 Å. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded to one O(3), one O(4), one O(5), one O(6), and two equivalent O(2) atoms to form RhO6 octahedra that share corners with four equivalent Rh(2)O6 octahedra and corners with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-57°. The Rh(1)-O(3) bond length is 2.08 Å. The Rh(1)-O(4) bond length is 1.99 Å. The Rh(1)-O(5) bond length is 2.56 Å. The Rh(1)-O(6) bond length is 2.05 Å. Both Rh(1)-O(2) bond lengths are 2.00 Å. In the second Rh site, Rh(2) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(2) atoms to form RhO6 octahedra that share corners with two equivalent Sb(1)O6 octahedra, corners with four equivalent Rh(1)O6 octahedra, and  a faceface with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-56°. The Rh(2)-O(3) bond length is 2.05 Å. The Rh(2)-O(5) bond length is 2.10 Å. Both Rh(2)-O(1) bond lengths are 2.23 Å. Both Rh(2)-O(2) bond lengths are 2.09 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(5), one O(6), two equivalent O(1), and two equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Rh(2)O6 octahedra, corners with four equivalent Rh(1)O6 octahedra, and  a faceface with one Rh(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-57°. The Sb(1)-O(5) bond length is 1.98 Å. The Sb(1)-O(6) bond length is 2.01 Å. Both Sb(1)-O(1) bond lengths are 2.10 Å. Both Sb(1)-O(2) bond lengths are 2.18 Å. In the second Sb site, Sb(2) is bonded in a distorted see-saw-like geometry to one O(4), one O(6), and two equivalent O(1) atoms. The Sb(2)-O(4) bond length is 2.00 Å. The Sb(2)-O(6) bond length is 2.33 Å. Both Sb(2)-O(1) bond lengths are 2.13 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate 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 in a 3-coordinate geometry to one Rh(1), one Rh(2), and one Sb(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Mg(1), one Rh(1), and one Rh(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Mg(1), one Rh(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Rh(1), one Rh(2), and one Sb(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Rh(1), one Sb(1), and one Sb(2) atom.