MgMn2(FeO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form distorted MgO6 octahedra that share corners with six equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-7°. There are two 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), one O(7), and one O(8) atom to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(4)O6 octahedra. In the second Mn site, Mn(2) is bonded to one O(1), one O(3), one O(4), one O(5), one O(7), and one O(8) atom 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 Fe(3)O6 octahedra, and edges with two equivalent Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-7°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted rectangular see-saw-like geometry to one O(5), one O(6), one O(7), and one O(8) atom. In the second Fe site, Fe(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(8) atom to form FeO6 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 Fe(4)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 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 Fe(3)O6 octahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mn(1), one Mn(2), one Fe(2), and one Fe(3) atom to form distorted OMgMn2Fe2 square pyramids that share  a cornercorner with one O(7)MgMn2Fe2 square pyramid,  a cornercorner with one O(5)MgMnFe3 trigonal bipyramid, corners with four equivalent O(8)MgMn2Fe2 trigonal bipyramids,  a cornercorner with one O(2)MnFe3 trigonal pyramid, corners with two equivalent O(6)MnFe3 trigonal pyramids,  an edgeedge with one O(7)MgMn2Fe2 square pyramid, edges with two equivalent O(3)MgMn2Fe2 square pyramids, edges with two equivalent O(4)MgMnFe3 square pyramids,  an edgeedge with one O(5)MgMnFe3 trigonal bipyramid, and  an edgeedge with one O(2)MnFe3 trigonal pyramid. In the second O site, O(2) is bonded to one Mn(1), one Fe(2), one Fe(3), and one Fe(4) atom to form distorted OMnFe3 trigonal pyramids that share  a cornercorner with one O(1)MgMn2Fe2 square pyramid,  a cornercorner with one O(3)MgMn2Fe2 square pyramid,  a cornercorner with one O(4)MgMnFe3 square pyramid, corners with two equivalent O(7)MgMn2Fe2 square pyramids, corners with two equivalent O(8)MgMn2Fe2 trigonal bipyramids, corners with two equivalent O(5)MgMnFe3 trigonal bipyramids, corners with three equivalent O(6)MnFe3 trigonal pyramids,  an edgeedge with one O(1)MgMn2Fe2 square pyramid,  an edgeedge with one O(3)MgMn2Fe2 square pyramid, and  an edgeedge with one O(4)MgMnFe3 square pyramid. In the third O site, O(3) is bonded to one Mg(1), one Mn(1), one Mn(2), one Fe(2), and one Fe(4) atom to form OMgMn2Fe2 square pyramids that share corners with four equivalent O(7)MgMn2Fe2 square pyramids,  a cornercorner with one O(8)MgMn2Fe2 trigonal bipyramid,  a cornercorner with one O(5)MgMnFe3 trigonal bipyramid,  a cornercorner with one O(2)MnFe3 trigonal pyramid, corners with two equivalent O(6)MnFe3 trigonal pyramids, edges with two equivalent O(1)MgMn2Fe2 square pyramids, edges with two equivalent O(4)MgMnFe3 square pyramids,  an edgeedge with one O(8)MgMn2Fe2 trigonal bipyramid,  an edgeedge with one O(5)MgMnFe3 trigonal bipyramid, and  an edgeedge with one O(2)MnFe3 trigonal pyramid. In the fourth O site, O(4) is bonded to one Mg(1), one Mn(2), one Fe(2), one Fe(3), and one Fe(4) atom to form OMgMnFe3 square pyramids that share  a cornercorner with one O(7)MgMn2Fe2 square pyramid,  a cornercorner with one O(8)MgMn2Fe2 trigonal bipyramid, corners with four equivalent O(5)MgMnFe3 trigonal bipyramids,  a cornercorner with one O(2)MnFe3 trigonal pyramid, corners with two equivalent O(6)MnFe3 trigonal pyramids,  an edgeedge with one O(7)MgMn2Fe2 square pyramid, edges with two equivalent O(1)MgMn2Fe2 square pyramids, edges with two equivalent O(3)MgMn2Fe2 square pyramids,  an edgeedge with one O(8)MgMn2Fe2 trigonal bipyramid, and  an edgeedge with one O(2)MnFe3 trigonal pyramid. In the fifth O site, O(5) is bonded to one Mg(1), one Mn(2), one Fe(1), one Fe(3), and one Fe(4) atom to form OMgMnFe3 trigonal bipyramids that share  a cornercorner with one O(1)MgMn2Fe2 square pyramid,  a cornercorner with one O(3)MgMn2Fe2 square pyramid, corners with four equivalent O(4)MgMnFe3 square pyramids,  a cornercorner with one O(6)MnFe3 trigonal pyramid, corners with two equivalent O(2)MnFe3 trigonal pyramids,  an edgeedge with one O(1)MgMn2Fe2 square pyramid,  an edgeedge with one O(3)MgMn2Fe2 square pyramid, edges with two equivalent O(7)MgMn2Fe2 square pyramids, edges with two equivalent O(8)MgMn2Fe2 trigonal bipyramids, and  an edgeedge with one O(6)MnFe3 trigonal pyramid. In the sixth O site, O(6) is bonded to one Mn(1), one Fe(1), one Fe(3), and one Fe(4) atom to form distorted OMnFe3 trigonal pyramids that share  a cornercorner with one O(7)MgMn2Fe2 square pyramid, corners with two equivalent O(1)MgMn2Fe2 square pyramids, corners with two equivalent O(3)MgMn2Fe2 square pyramids, corners with two equivalent O(4)MgMnFe3 square pyramids,  a cornercorner with one O(8)MgMn2Fe2 trigonal bipyramid,  a cornercorner with one O(5)MgMnFe3 trigonal bipyramid, corners with three equivalent O(2)MnFe3 trigonal pyramids,  an edgeedge with one O(7)MgMn2Fe2 square pyramid,  an edgeedge with one O(8)MgMn2Fe2 trigonal bipyramid, and  an edgeedge with one O(5)MgMnFe3 trigonal bipyramid. In the seventh O site, O(7) is bonded to one Mg(1), one Mn(1), one Mn(2), one Fe(1), and one Fe(4) atom to form distorted OMgMn2Fe2 square pyramids that share  a cornercorner with one O(1)MgMn2Fe2 square pyramid,  a cornercorner with one O(4)MgMnFe3 square pyramid, corners with four equivalent O(3)MgMn2Fe2 square pyramids,  a cornercorner with one O(6)MnFe3 trigonal pyramid, corners with two equivalent O(2)MnFe3 trigonal pyramids,  an edgeedge with one O(1)MgMn2Fe2 square pyramid,  an edgeedge with one O(4)MgMnFe3 square pyramid, edges with two equivalent O(8)MgMn2Fe2 trigonal bipyramids, edges with two equivalent O(5)MgMnFe3 trigonal bipyramids, and  an edgeedge with one O(6)MnFe3 trigonal pyramid. In the eighth O site, O(8) is bonded to one Mg(1), one Mn(1), one Mn(2), one Fe(1), and one Fe(3) atom to form OMgMn2Fe2 trigonal bipyramids that share  a cornercorner with one O(3)MgMn2Fe2 square pyramid,  a cornercorner with one O(4)MgMnFe3 square pyramid, corners with four equivalent O(1)MgMn2Fe2 square pyramids,  a cornercorner with one O(6)MnFe3 trigonal pyramid, corners with two equivalent O(2)MnFe3 trigonal pyramids,  an edgeedge with one O(3)MgMn2Fe2 square pyramid,  an edgeedge with one O(4)MgMnFe3 square pyramid, edges with two equivalent O(7)MgMn2Fe2 square pyramids, edges with two equivalent O(5)MgMnFe3 trigonal bipyramids, and  an edgeedge with one O(6)MnFe3 trigonal pyramid.
MgMn2(FeO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form distorted MgO6 octahedra that share corners with six equivalent Mn(2)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-7°. The Mg(1)-O(1) bond length is 2.27 Å. The Mg(1)-O(3) bond length is 2.20 Å. The Mg(1)-O(4) bond length is 2.10 Å. The Mg(1)-O(5) bond length is 2.11 Å. The Mg(1)-O(7) bond length is 2.06 Å. The Mg(1)-O(8) bond length is 2.08 Å. There are two 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), one O(7), and one O(8) atom to form MnO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Fe(4)O6 octahedra. The Mn(1)-O(1) bond length is 2.25 Å. The Mn(1)-O(2) bond length is 2.11 Å. The Mn(1)-O(3) bond length is 2.25 Å. The Mn(1)-O(6) bond length is 2.10 Å. The Mn(1)-O(7) bond length is 2.23 Å. The Mn(1)-O(8) bond length is 2.19 Å. In the second Mn site, Mn(2) is bonded to one O(1), one O(3), one O(4), one O(5), one O(7), and one O(8) atom 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 Fe(3)O6 octahedra, and edges with two equivalent Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 3-7°. The Mn(2)-O(1) bond length is 2.29 Å. The Mn(2)-O(3) bond length is 2.35 Å. The Mn(2)-O(4) bond length is 2.24 Å. The Mn(2)-O(5) bond length is 2.37 Å. The Mn(2)-O(7) bond length is 2.29 Å. The Mn(2)-O(8) bond length is 2.20 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a distorted rectangular see-saw-like geometry to one O(5), one O(6), one O(7), and one O(8) atom. The Fe(1)-O(5) bond length is 2.04 Å. The Fe(1)-O(6) bond length is 1.88 Å. The Fe(1)-O(7) bond length is 2.31 Å. The Fe(1)-O(8) bond length is 2.10 Å. In the second Fe site, Fe(2) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Fe(2)-O(1) bond length is 1.93 Å. The Fe(2)-O(2) bond length is 1.89 Å. The Fe(2)-O(3) bond length is 1.98 Å. The Fe(2)-O(4) bond length is 2.05 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(8) atom to form FeO6 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 Fe(4)O6 octahedra. The Fe(3)-O(1) bond length is 2.28 Å. The Fe(3)-O(2) bond length is 2.04 Å. The Fe(3)-O(4) bond length is 2.31 Å. The Fe(3)-O(5) bond length is 2.24 Å. The Fe(3)-O(6) bond length is 2.00 Å. The Fe(3)-O(8) bond length is 2.18 Å. In the fourth Fe site, Fe(4) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 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 Fe(3)O6 octahedra. The Fe(4)-O(2) bond length is 2.02 Å. The Fe(4)-O(3) bond length is 2.22 Å. The Fe(4)-O(4) bond length is 2.26 Å. The Fe(4)-O(5) bond length is 2.04 Å. The Fe(4)-O(6) bond length is 1.96 Å. The Fe(4)-O(7) bond length is 2.04 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mn(1), one Mn(2), one Fe(2), and one Fe(3) atom to form distorted OMgMn2Fe2 square pyramids that share  a cornercorner with one O(7)MgMn2Fe2 square pyramid,  a cornercorner with one O(5)MgMnFe3 trigonal bipyramid, corners with four equivalent O(8)MgMn2Fe2 trigonal bipyramids,  a cornercorner with one O(2)MnFe3 trigonal pyramid, corners with two equivalent O(6)MnFe3 trigonal pyramids,  an edgeedge with one O(7)MgMn2Fe2 square pyramid, edges with two equivalent O(3)MgMn2Fe2 square pyramids, edges with two equivalent O(4)MgMnFe3 square pyramids,  an edgeedge with one O(5)MgMnFe3 trigonal bipyramid, and  an edgeedge with one O(2)MnFe3 trigonal pyramid. In the second O site, O(2) is bonded to one Mn(1), one Fe(2), one Fe(3), and one Fe(4) atom to form distorted OMnFe3 trigonal pyramids that share  a cornercorner with one O(1)MgMn2Fe2 square pyramid,  a cornercorner with one O(3)MgMn2Fe2 square pyramid,  a cornercorner with one O(4)MgMnFe3 square pyramid, corners with two equivalent O(7)MgMn2Fe2 square pyramids, corners with two equivalent O(8)MgMn2Fe2 trigonal bipyramids, corners with two equivalent O(5)MgMnFe3 trigonal bipyramids, corners with three equivalent O(6)MnFe3 trigonal pyramids,  an edgeedge with one O(1)MgMn2Fe2 square pyramid,  an edgeedge with one O(3)MgMn2Fe2 square pyramid, and  an edgeedge with one O(4)MgMnFe3 square pyramid. In the third O site, O(3) is bonded to one Mg(1), one Mn(1), one Mn(2), one Fe(2), and one Fe(4) atom to form OMgMn2Fe2 square pyramids that share corners with four equivalent O(7)MgMn2Fe2 square pyramids,  a cornercorner with one O(8)MgMn2Fe2 trigonal bipyramid,  a cornercorner with one O(5)MgMnFe3 trigonal bipyramid,  a cornercorner with one O(2)MnFe3 trigonal pyramid, corners with two equivalent O(6)MnFe3 trigonal pyramids, edges with two equivalent O(1)MgMn2Fe2 square pyramids, edges with two equivalent O(4)MgMnFe3 square pyramids,  an edgeedge with one O(8)MgMn2Fe2 trigonal bipyramid,  an edgeedge with one O(5)MgMnFe3 trigonal bipyramid, and  an edgeedge with one O(2)MnFe3 trigonal pyramid. In the fourth O site, O(4) is bonded to one Mg(1), one Mn(2), one Fe(2), one Fe(3), and one Fe(4) atom to form OMgMnFe3 square pyramids that share  a cornercorner with one O(7)MgMn2Fe2 square pyramid,  a cornercorner with one O(8)MgMn2Fe2 trigonal bipyramid, corners with four equivalent O(5)MgMnFe3 trigonal bipyramids,  a cornercorner with one O(2)MnFe3 trigonal pyramid, corners with two equivalent O(6)MnFe3 trigonal pyramids,  an edgeedge with one O(7)MgMn2Fe2 square pyramid, edges with two equivalent O(1)MgMn2Fe2 square pyramids, edges with two equivalent O(3)MgMn2Fe2 square pyramids,  an edgeedge with one O(8)MgMn2Fe2 trigonal bipyramid, and  an edgeedge with one O(2)MnFe3 trigonal pyramid. In the fifth O site, O(5) is bonded to one Mg(1), one Mn(2), one Fe(1), one Fe(3), and one Fe(4) atom to form OMgMnFe3 trigonal bipyramids that share  a cornercorner with one O(1)MgMn2Fe2 square pyramid,  a cornercorner with one O(3)MgMn2Fe2 square pyramid, corners with four equivalent O(4)MgMnFe3 square pyramids,  a cornercorner with one O(6)MnFe3 trigonal pyramid, corners with two equivalent O(2)MnFe3 trigonal pyramids,  an edgeedge with one O(1)MgMn2Fe2 square pyramid,  an edgeedge with one O(3)MgMn2Fe2 square pyramid, edges with two equivalent O(7)MgMn2Fe2 square pyramids, edges with two equivalent O(8)MgMn2Fe2 trigonal bipyramids, and  an edgeedge with one O(6)MnFe3 trigonal pyramid. In the sixth O site, O(6) is bonded to one Mn(1), one Fe(1), one Fe(3), and one Fe(4) atom to form distorted OMnFe3 trigonal pyramids that share  a cornercorner with one O(7)MgMn2Fe2 square pyramid, corners with two equivalent O(1)MgMn2Fe2 square pyramids, corners with two equivalent O(3)MgMn2Fe2 square pyramids, corners with two equivalent O(4)MgMnFe3 square pyramids,  a cornercorner with one O(8)MgMn2Fe2 trigonal bipyramid,  a cornercorner with one O(5)MgMnFe3 trigonal bipyramid, corners with three equivalent O(2)MnFe3 trigonal pyramids,  an edgeedge with one O(7)MgMn2Fe2 square pyramid,  an edgeedge with one O(8)MgMn2Fe2 trigonal bipyramid, and  an edgeedge with one O(5)MgMnFe3 trigonal bipyramid. In the seventh O site, O(7) is bonded to one Mg(1), one Mn(1), one Mn(2), one Fe(1), and one Fe(4) atom to form distorted OMgMn2Fe2 square pyramids that share  a cornercorner with one O(1)MgMn2Fe2 square pyramid,  a cornercorner with one O(4)MgMnFe3 square pyramid, corners with four equivalent O(3)MgMn2Fe2 square pyramids,  a cornercorner with one O(6)MnFe3 trigonal pyramid, corners with two equivalent O(2)MnFe3 trigonal pyramids,  an edgeedge with one O(1)MgMn2Fe2 square pyramid,  an edgeedge with one O(4)MgMnFe3 square pyramid, edges with two equivalent O(8)MgMn2Fe2 trigonal bipyramids, edges with two equivalent O(5)MgMnFe3 trigonal bipyramids, and  an edgeedge with one O(6)MnFe3 trigonal pyramid. In the eighth O site, O(8) is bonded to one Mg(1), one Mn(1), one Mn(2), one Fe(1), and one Fe(3) atom to form OMgMn2Fe2 trigonal bipyramids that share  a cornercorner with one O(3)MgMn2Fe2 square pyramid,  a cornercorner with one O(4)MgMnFe3 square pyramid, corners with four equivalent O(1)MgMn2Fe2 square pyramids,  a cornercorner with one O(6)MnFe3 trigonal pyramid, corners with two equivalent O(2)MnFe3 trigonal pyramids,  an edgeedge with one O(3)MgMn2Fe2 square pyramid,  an edgeedge with one O(4)MgMnFe3 square pyramid, edges with two equivalent O(7)MgMn2Fe2 square pyramids, edges with two equivalent O(5)MgMnFe3 trigonal bipyramids, and  an edgeedge with one O(6)MnFe3 trigonal pyramid.