MgMn3SbO8 is beta indium sulfide-derived structured and crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-21°. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. In the third Mn site, Mn(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-21°. Sb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form SbO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Mn(3)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Mn(1), one Mn(2), and one Mn(3) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(2), one Mn(3), and one Sb(1) atom. In the third O site, O(3) is bonded in a see-saw-like geometry to one Mg(1), one Mn(1), one Mn(3), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one Sb(1) atom.
MgMn3SbO8 is beta indium sulfide-derived structured and crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Mn(3)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-21°. Both Mg(1)-O(1) bond lengths are 2.11 Å. Both Mg(1)-O(2) bond lengths are 2.17 Å. Both Mg(1)-O(3) bond lengths are 2.19 Å. There are three inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. Both Mn(1)-O(1) bond lengths are 1.96 Å. Both Mn(1)-O(3) bond lengths are 1.98 Å. Both Mn(1)-O(4) bond lengths are 2.34 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(3)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. Both Mn(2)-O(1) bond lengths are 1.96 Å. Both Mn(2)-O(2) bond lengths are 1.98 Å. Both Mn(2)-O(4) bond lengths are 1.97 Å. In the third Mn site, Mn(3) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-21°. Both Mn(3)-O(1) bond lengths are 2.17 Å. Both Mn(3)-O(2) bond lengths are 2.34 Å. Both Mn(3)-O(3) bond lengths are 2.20 Å. Sb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form SbO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Mn(3)O6 octahedra. Both Sb(1)-O(2) bond lengths are 2.04 Å. Both Sb(1)-O(3) bond lengths are 2.03 Å. Both Sb(1)-O(4) bond lengths are 2.00 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Mg(1), one Mn(1), one Mn(2), and one Mn(3) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(2), one Mn(3), and one Sb(1) atom. In the third O site, O(3) is bonded in a see-saw-like geometry to one Mg(1), one Mn(1), one Mn(3), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Mn(1), one Mn(2), and one Sb(1) atom.