MgMn6(O3F)3 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent F(2) atoms to form MgO4F2 octahedra that share corners with four equivalent Mn(1)O4F2 octahedra and faces with two equivalent Mn(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-46°. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to one O(1), one O(2), one O(4), one O(6), one F(1), and one F(2) atom to form MnO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with three equivalent Mn(4)O4F square pyramids,  an edgeedge with one Mn(1)O4F2 octahedra, and  an edgeedge with one Mn(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-46°. In the second Mn site, Mn(2) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent F(2) atoms to form MnO4F2 octahedra that share edges with two equivalent Mn(1)O4F2 octahedra and faces with two equivalent Mg(1)O4F2 octahedra. In the third Mn site, Mn(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. In the fourth Mn site, Mn(4) is bonded to two equivalent O(2), two equivalent O(4), and one F(1) atom to form corner-sharing MnO4F square pyramids. The corner-sharing octahedral tilt angles range from 43-52°. 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 Mn(1), one Mn(2), and one Mn(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one Mn(4) atom. In the third O site, O(3) is bonded to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms to form a mixture of distorted corner and edge-sharing OMgMn3 trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one Mn(4) atom. In the fifth O site, O(5) is bonded to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms to form a mixture of corner and edge-sharing OMgMn3 trigonal pyramids. In the sixth O site, O(6) is bonded in a water-like geometry to two equivalent Mn(1) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Mn(4) and two equivalent Mn(1) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Mn(1), and one Mn(2) atom.
MgMn6(O3F)3 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent F(2) atoms to form MgO4F2 octahedra that share corners with four equivalent Mn(1)O4F2 octahedra and faces with two equivalent Mn(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-46°. The Mg(1)-O(3) bond length is 1.97 Å. The Mg(1)-O(5) bond length is 2.00 Å. Both Mg(1)-O(1) bond lengths are 2.12 Å. Both Mg(1)-F(2) bond lengths are 2.00 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(4), one O(6), one F(1), and one F(2) atom to form MnO4F2 octahedra that share corners with two equivalent Mg(1)O4F2 octahedra, corners with three equivalent Mn(4)O4F square pyramids,  an edgeedge with one Mn(1)O4F2 octahedra, and  an edgeedge with one Mn(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 43-46°. The Mn(1)-O(1) bond length is 2.04 Å. The Mn(1)-O(2) bond length is 1.98 Å. The Mn(1)-O(4) bond length is 1.99 Å. The Mn(1)-O(6) bond length is 1.86 Å. The Mn(1)-F(1) bond length is 2.16 Å. The Mn(1)-F(2) bond length is 2.35 Å. In the second Mn site, Mn(2) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent F(2) atoms to form MnO4F2 octahedra that share edges with two equivalent Mn(1)O4F2 octahedra and faces with two equivalent Mg(1)O4F2 octahedra. The Mn(2)-O(3) bond length is 2.02 Å. The Mn(2)-O(5) bond length is 1.97 Å. Both Mn(2)-O(1) bond lengths are 1.87 Å. Both Mn(2)-F(2) bond lengths are 2.01 Å. In the third Mn site, Mn(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. The Mn(3)-O(1) bond length is 2.37 Å. The Mn(3)-O(2) bond length is 1.89 Å. The Mn(3)-O(3) bond length is 2.01 Å. The Mn(3)-O(4) bond length is 1.91 Å. The Mn(3)-O(5) bond length is 2.01 Å. In the fourth Mn site, Mn(4) is bonded to two equivalent O(2), two equivalent O(4), and one F(1) atom to form corner-sharing MnO4F square pyramids. The corner-sharing octahedral tilt angles range from 43-52°. Both Mn(4)-O(2) bond lengths are 1.96 Å. Both Mn(4)-O(4) bond lengths are 1.96 Å. The Mn(4)-F(1) bond length is 2.19 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 Mn(1), one Mn(2), and one Mn(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one Mn(4) atom. In the third O site, O(3) is bonded to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms to form a mixture of distorted corner and edge-sharing OMgMn3 trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mn(1), one Mn(3), and one Mn(4) atom. In the fifth O site, O(5) is bonded to one Mg(1), one Mn(2), and two equivalent Mn(3) atoms to form a mixture of corner and edge-sharing OMgMn3 trigonal pyramids. In the sixth O site, O(6) is bonded in a water-like geometry to two equivalent Mn(1) atoms. There are two inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Mn(4) and two equivalent Mn(1) atoms. In the second F site, F(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Mn(1), and one Mn(2) atom.