MgMn2(OF)2 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded to two equivalent O(1) and two equivalent F(1) atoms to form MgO2F2 tetrahedra that share corners with four equivalent Mn(2)O4F2 octahedra, corners with two equivalent Mg(1)O2F2 tetrahedra, and  an edgeedge with one Mn(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 12-55°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent F(1) atoms. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent F(1) atoms to form MnO4F2 octahedra that share corners with four equivalent Mg(1)O2F2 tetrahedra, edges with two equivalent Mn(2)O4F2 octahedra, and  an edgeedge with one Mg(1)O2F2 tetrahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Mn(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mn(1) and two equivalent Mn(2) atoms. F(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(2), and two equivalent Mn(1) atoms.
MgMn2(OF)2 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded to two equivalent O(1) and two equivalent F(1) atoms to form MgO2F2 tetrahedra that share corners with four equivalent Mn(2)O4F2 octahedra, corners with two equivalent Mg(1)O2F2 tetrahedra, and  an edgeedge with one Mn(2)O4F2 octahedra. The corner-sharing octahedral tilt angles range from 12-55°. Both Mg(1)-O(1) bond lengths are 1.92 Å. Both Mg(1)-F(1) bond lengths are 2.03 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent F(1) atoms. The Mn(1)-O(2) bond length is 1.89 Å. All Mn(1)-F(1) bond lengths are 2.27 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent F(1) atoms to form MnO4F2 octahedra that share corners with four equivalent Mg(1)O2F2 tetrahedra, edges with two equivalent Mn(2)O4F2 octahedra, and  an edgeedge with one Mg(1)O2F2 tetrahedra. Both Mn(2)-O(1) bond lengths are 2.31 Å. Both Mn(2)-O(2) bond lengths are 2.05 Å. Both Mn(2)-F(1) bond lengths are 2.39 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Mg(1) and two equivalent Mn(2) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Mn(1) and two equivalent Mn(2) atoms. F(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Mn(2), and two equivalent Mn(1) atoms.