MgMn6(OF)6 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(2), two equivalent O(1), one F(3), and two equivalent F(4) atoms to form MgO3F3 octahedra that share corners with two equivalent Mn(2)O3F3 octahedra, corners with two equivalent Mn(1)O3F2 square pyramids, edges with two equivalent Mn(2)O3F3 octahedra, and edges with four equivalent Mn(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 1-38°. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), one O(4), one F(1), and one F(2) atom to form MnO3F2 square pyramids that share  a cornercorner with one Mg(1)O3F3 octahedra,  a cornercorner with one Mn(2)O3F3 octahedra, corners with three equivalent Mn(3)O3F3 octahedra, and  an edgeedge with one Mn(1)O3F2 square pyramid. The corner-sharing octahedral tilt angles range from 43-58°. In the second Mn site, Mn(2) is bonded to one O(2), two equivalent O(1), one F(3), and two equivalent F(4) atoms to form distorted MnO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with two equivalent Mn(1)O3F2 square pyramids, edges with two equivalent Mg(1)O3F3 octahedra, and edges with four equivalent Mn(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 1-38°. In the third Mn site, Mn(3) is bonded to one O(1), one O(2), one O(3), one F(2), one F(3), and one F(4) atom to form distorted MnO3F3 octahedra that share corners with three equivalent Mn(1)O3F2 square pyramids,  an edgeedge with one Mn(3)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Mn(2)O3F3 octahedra. In the fourth Mn site, Mn(4) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(3), and two equivalent F(2) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular 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 tetrahedral geometry to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mn(1), one Mn(3), and one Mn(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mn(4) and two equivalent Mn(1) atoms. There are four inequivalent F sites. In the first F site, F(1) is bonded in an L-shaped geometry to two equivalent Mn(1) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(3), and one Mn(4) atom. In the third F site, F(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Mn(2), and one Mn(3) atom.
MgMn6(OF)6 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(2), two equivalent O(1), one F(3), and two equivalent F(4) atoms to form MgO3F3 octahedra that share corners with two equivalent Mn(2)O3F3 octahedra, corners with two equivalent Mn(1)O3F2 square pyramids, edges with two equivalent Mn(2)O3F3 octahedra, and edges with four equivalent Mn(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 1-38°. The Mg(1)-O(2) bond length is 1.95 Å. Both Mg(1)-O(1) bond lengths are 2.15 Å. The Mg(1)-F(3) bond length is 1.96 Å. Both Mg(1)-F(4) bond lengths are 2.04 Å. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(3), one O(4), one F(1), and one F(2) atom to form MnO3F2 square pyramids that share  a cornercorner with one Mg(1)O3F3 octahedra,  a cornercorner with one Mn(2)O3F3 octahedra, corners with three equivalent Mn(3)O3F3 octahedra, and  an edgeedge with one Mn(1)O3F2 square pyramid. The corner-sharing octahedral tilt angles range from 43-58°. The Mn(1)-O(1) bond length is 2.03 Å. The Mn(1)-O(3) bond length is 1.93 Å. The Mn(1)-O(4) bond length is 1.95 Å. The Mn(1)-F(1) bond length is 2.07 Å. The Mn(1)-F(2) bond length is 2.02 Å. In the second Mn site, Mn(2) is bonded to one O(2), two equivalent O(1), one F(3), and two equivalent F(4) atoms to form distorted MnO3F3 octahedra that share corners with two equivalent Mg(1)O3F3 octahedra, corners with two equivalent Mn(1)O3F2 square pyramids, edges with two equivalent Mg(1)O3F3 octahedra, and edges with four equivalent Mn(3)O3F3 octahedra. The corner-sharing octahedral tilt angles range from 1-38°. The Mn(2)-O(2) bond length is 2.00 Å. Both Mn(2)-O(1) bond lengths are 2.15 Å. The Mn(2)-F(3) bond length is 2.11 Å. Both Mn(2)-F(4) bond lengths are 2.42 Å. In the third Mn site, Mn(3) is bonded to one O(1), one O(2), one O(3), one F(2), one F(3), and one F(4) atom to form distorted MnO3F3 octahedra that share corners with three equivalent Mn(1)O3F2 square pyramids,  an edgeedge with one Mn(3)O3F3 octahedra, edges with two equivalent Mg(1)O3F3 octahedra, and edges with two equivalent Mn(2)O3F3 octahedra. The Mn(3)-O(1) bond length is 1.97 Å. The Mn(3)-O(2) bond length is 2.01 Å. The Mn(3)-O(3) bond length is 1.87 Å. The Mn(3)-F(2) bond length is 2.14 Å. The Mn(3)-F(3) bond length is 2.34 Å. The Mn(3)-F(4) bond length is 2.05 Å. In the fourth Mn site, Mn(4) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(3), and two equivalent F(2) atoms. The Mn(4)-O(4) bond length is 2.05 Å. Both Mn(4)-O(3) bond lengths are 2.08 Å. Both Mn(4)-F(2) bond lengths are 2.33 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular 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 tetrahedral geometry to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mn(1), one Mn(3), and one Mn(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mn(4) and two equivalent Mn(1) atoms. There are four inequivalent F sites. In the first F site, F(1) is bonded in an L-shaped geometry to two equivalent Mn(1) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mn(1), one Mn(3), and one Mn(4) atom. In the third F site, F(3) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms. In the fourth F site, F(4) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Mn(2), and one Mn(3) atom.