MgMn(SbO3)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Sb(2)O6 octahedra and edges with two equivalent Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. Mn(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and one O(6) atom. In the second Sb site, Sb(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form SbO6 octahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid and edges with two equivalent Mg(1)O5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mn(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Sb(1), and one Sb(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded in a trigonal pyramidal geometry to one Mg(1), one Mn(1), one Sb(1), and one Sb(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Sb(1), and one Sb(2) atom.
MgMn(SbO3)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Sb(2)O6 octahedra and edges with two equivalent Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles are 46°. The Mg(1)-O(2) bond length is 2.05 Å. The Mg(1)-O(3) bond length is 2.05 Å. The Mg(1)-O(4) bond length is 2.09 Å. The Mg(1)-O(5) bond length is 2.23 Å. The Mg(1)-O(6) bond length is 2.06 Å. Mn(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. The Mn(1)-O(1) bond length is 2.03 Å. The Mn(1)-O(2) bond length is 2.04 Å. The Mn(1)-O(3) bond length is 2.12 Å. The Mn(1)-O(4) bond length is 2.79 Å. The Mn(1)-O(5) bond length is 2.21 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and one O(6) atom. The Sb(1)-O(1) bond length is 2.25 Å. The Sb(1)-O(3) bond length is 2.62 Å. The Sb(1)-O(4) bond length is 2.14 Å. The Sb(1)-O(5) bond length is 2.09 Å. The Sb(1)-O(6) bond length is 2.29 Å. In the second Sb site, Sb(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form SbO6 octahedra that share  a cornercorner with one Mg(1)O5 trigonal bipyramid and edges with two equivalent Mg(1)O5 trigonal bipyramids. The Sb(2)-O(1) bond length is 1.98 Å. The Sb(2)-O(2) bond length is 2.08 Å. The Sb(2)-O(3) bond length is 1.97 Å. The Sb(2)-O(4) bond length is 2.09 Å. The Sb(2)-O(5) bond length is 2.07 Å. The Sb(2)-O(6) bond length is 2.00 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mn(1), one Sb(1), and one Sb(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Mn(1), and one Sb(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Sb(1), and one Sb(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Sb(1), and one Sb(2) atom. In the fifth O site, O(5) is bonded in a trigonal pyramidal geometry to one Mg(1), one Mn(1), one Sb(1), and one Sb(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Sb(1), and one Sb(2) atom.