MgMn6(O2F)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(4), one O(5), two equivalent O(2), and two equivalent F(2) atoms to form MgO4F2 octahedra that share corners with four equivalent Mn(1)O4F trigonal bipyramids and edges with four equivalent Mn(3)O4F2 octahedra. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one F(2) atom to form MnO4F trigonal bipyramids that share corners with two equivalent Mg(1)O4F2 octahedra, corners with three equivalent Mn(3)O4F2 octahedra, corners with three equivalent Mn(4)O4F2 octahedra, and  an edgeedge with one Mn(1)O4F trigonal bipyramid. The corner-sharing octahedral tilt angles range from 27-61°. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(4), one O(5), two equivalent O(2), and two equivalent F(2) atoms. In the third Mn site, Mn(3) is bonded to one O(2), one O(3), one O(4), one O(5), one F(1), and one F(2) atom to form MnO4F2 octahedra that share corners with three equivalent Mn(1)O4F trigonal bipyramids,  an edgeedge with one Mn(3)O4F2 octahedra,  an edgeedge with one Mn(4)O4F2 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. In the fourth Mn site, Mn(4) is bonded to one O(1), one O(6), two equivalent O(3), and two equivalent F(1) atoms to form MnO4F2 octahedra that share corners with six equivalent Mn(1)O4F trigonal bipyramids and edges with two equivalent Mn(3)O4F2 octahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mn(4) and two equivalent Mn(1) atoms. In the second O site, O(2) 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 third O site, O(3) is bonded in a distorted 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 rectangular see-saw-like geometry to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms. In the fifth O site, O(5) is bonded in a trigonal pyramidal geometry to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mn(4) and two equivalent Mn(1) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in an L-shaped geometry to one Mn(3) and one Mn(4) atom. In the second F site, F(2) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Mn(2), and one Mn(3) atom.
MgMn6(O2F)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(4), one O(5), two equivalent O(2), and two equivalent F(2) atoms to form MgO4F2 octahedra that share corners with four equivalent Mn(1)O4F trigonal bipyramids and edges with four equivalent Mn(3)O4F2 octahedra. The Mg(1)-O(4) bond length is 1.99 Å. The Mg(1)-O(5) bond length is 2.03 Å. Both Mg(1)-O(2) bond lengths are 2.09 Å. Both Mg(1)-F(2) bond lengths are 2.16 Å. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one F(2) atom to form MnO4F trigonal bipyramids that share corners with two equivalent Mg(1)O4F2 octahedra, corners with three equivalent Mn(3)O4F2 octahedra, corners with three equivalent Mn(4)O4F2 octahedra, and  an edgeedge with one Mn(1)O4F trigonal bipyramid. The corner-sharing octahedral tilt angles range from 27-61°. The Mn(1)-O(1) bond length is 1.95 Å. The Mn(1)-O(2) bond length is 1.94 Å. The Mn(1)-O(3) bond length is 2.13 Å. The Mn(1)-O(6) bond length is 1.91 Å. The Mn(1)-F(2) bond length is 2.18 Å. In the second Mn site, Mn(2) is bonded in a 6-coordinate geometry to one O(4), one O(5), two equivalent O(2), and two equivalent F(2) atoms. The Mn(2)-O(4) bond length is 2.22 Å. The Mn(2)-O(5) bond length is 1.94 Å. Both Mn(2)-O(2) bond lengths are 2.01 Å. Both Mn(2)-F(2) bond lengths are 2.66 Å. In the third Mn site, Mn(3) is bonded to one O(2), one O(3), one O(4), one O(5), one F(1), and one F(2) atom to form MnO4F2 octahedra that share corners with three equivalent Mn(1)O4F trigonal bipyramids,  an edgeedge with one Mn(3)O4F2 octahedra,  an edgeedge with one Mn(4)O4F2 octahedra, and edges with two equivalent Mg(1)O4F2 octahedra. The Mn(3)-O(2) bond length is 2.10 Å. The Mn(3)-O(3) bond length is 1.91 Å. The Mn(3)-O(4) bond length is 1.97 Å. The Mn(3)-O(5) bond length is 1.97 Å. The Mn(3)-F(1) bond length is 1.96 Å. The Mn(3)-F(2) bond length is 2.24 Å. In the fourth Mn site, Mn(4) is bonded to one O(1), one O(6), two equivalent O(3), and two equivalent F(1) atoms to form MnO4F2 octahedra that share corners with six equivalent Mn(1)O4F trigonal bipyramids and edges with two equivalent Mn(3)O4F2 octahedra. The Mn(4)-O(1) bond length is 2.11 Å. The Mn(4)-O(6) bond length is 2.24 Å. Both Mn(4)-O(3) bond lengths are 1.90 Å. Both Mn(4)-F(1) bond lengths are 2.01 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(4) and two equivalent Mn(1) atoms. In the second O site, O(2) 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 third O site, O(3) is bonded in a distorted 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 rectangular see-saw-like geometry to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms. In the fifth O site, O(5) is bonded in a trigonal pyramidal geometry to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Mn(4) and two equivalent Mn(1) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in an L-shaped geometry to one Mn(3) and one Mn(4) atom. In the second F site, F(2) is bonded in a 4-coordinate geometry to one Mg(1), one Mn(1), one Mn(2), and one Mn(3) atom.