MgFe2O5 is beta indium sulfide-derived structured and crystallizes in the orthorhombic Cmc2_1 space group. Mg(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 28-46°. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 30-46°. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Fe(1), and one Fe(2) atom to form distorted OMg2Fe2 trigonal pyramids that share  a cornercorner with one O(4)MgFe3 trigonal pyramid,  a cornercorner with one O(5)MgFe3 trigonal pyramid, corners with two equivalent O(1)Mg2Fe2 trigonal pyramids, edges with two equivalent O(4)MgFe3 trigonal pyramids, and edges with two equivalent O(5)MgFe3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(2) atoms to form OMgFe3 trigonal pyramids that share  a cornercorner with one O(1)Mg2Fe2 trigonal pyramid,  a cornercorner with one O(5)MgFe3 trigonal pyramid, corners with two equivalent O(4)MgFe3 trigonal pyramids, edges with two equivalent O(1)Mg2Fe2 trigonal pyramids, and edges with two equivalent O(5)MgFe3 trigonal pyramids. In the fifth O site, O(5) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(1) atoms to form OMgFe3 trigonal pyramids that share  a cornercorner with one O(1)Mg2Fe2 trigonal pyramid,  a cornercorner with one O(4)MgFe3 trigonal pyramid, corners with two equivalent O(5)MgFe3 trigonal pyramids, edges with two equivalent O(1)Mg2Fe2 trigonal pyramids, and edges with two equivalent O(4)MgFe3 trigonal pyramids.
MgFe2O5 is beta indium sulfide-derived structured and crystallizes in the orthorhombic Cmc2_1 space group. Mg(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms. The Mg(1)-O(2) bond length is 2.04 Å. The Mg(1)-O(3) bond length is 2.04 Å. The Mg(1)-O(4) bond length is 2.14 Å. The Mg(1)-O(5) bond length is 2.12 Å. Both Mg(1)-O(1) bond lengths are 2.11 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 28-46°. The Fe(1)-O(1) bond length is 1.94 Å. The Fe(1)-O(2) bond length is 1.88 Å. The Fe(1)-O(3) bond length is 1.84 Å. The Fe(1)-O(4) bond length is 1.99 Å. Both Fe(1)-O(5) bond lengths are 2.03 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(2), one O(3), one O(5), and two equivalent O(4) atoms to form a mixture of corner and edge-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 30-46°. The Fe(2)-O(1) bond length is 2.05 Å. The Fe(2)-O(2) bond length is 1.90 Å. The Fe(2)-O(3) bond length is 1.97 Å. The Fe(2)-O(5) bond length is 2.02 Å. Both Fe(2)-O(4) bond lengths are 2.03 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1), one Fe(1), and one Fe(2) atom to form distorted OMg2Fe2 trigonal pyramids that share  a cornercorner with one O(4)MgFe3 trigonal pyramid,  a cornercorner with one O(5)MgFe3 trigonal pyramid, corners with two equivalent O(1)Mg2Fe2 trigonal pyramids, edges with two equivalent O(4)MgFe3 trigonal pyramids, and edges with two equivalent O(5)MgFe3 trigonal pyramids. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the third O site, O(3) is bonded in a T-shaped geometry to one Mg(1), one Fe(1), and one Fe(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Fe(1), and two equivalent Fe(2) atoms to form OMgFe3 trigonal pyramids that share  a cornercorner with one O(1)Mg2Fe2 trigonal pyramid,  a cornercorner with one O(5)MgFe3 trigonal pyramid, corners with two equivalent O(4)MgFe3 trigonal pyramids, edges with two equivalent O(1)Mg2Fe2 trigonal pyramids, and edges with two equivalent O(5)MgFe3 trigonal pyramids. In the fifth O site, O(5) is bonded to one Mg(1), one Fe(2), and two equivalent Fe(1) atoms to form OMgFe3 trigonal pyramids that share  a cornercorner with one O(1)Mg2Fe2 trigonal pyramid,  a cornercorner with one O(4)MgFe3 trigonal pyramid, corners with two equivalent O(5)MgFe3 trigonal pyramids, edges with two equivalent O(1)Mg2Fe2 trigonal pyramids, and edges with two equivalent O(4)MgFe3 trigonal pyramids.