MgFe2O4 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(1) atoms. Fe(1) is bonded to one O(3), two equivalent O(2), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-57°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and three equivalent Fe(1) atoms to form distorted OMg2Fe3 trigonal bipyramids that share corners with five equivalent O(3)Mg2Fe2 tetrahedra, corners with two equivalent O(1)Mg2Fe3 trigonal bipyramids,  an edgeedge with one O(3)Mg2Fe2 tetrahedra, and edges with five equivalent O(1)Mg2Fe3 trigonal bipyramids. In the second O site, O(2) is bonded in a square co-planar geometry to four equivalent Fe(1) atoms. In the third O site, O(3) is bonded to two equivalent Mg(1) and two equivalent Fe(1) atoms to form OMg2Fe2 tetrahedra that share corners with two equivalent O(3)Mg2Fe2 tetrahedra, corners with ten equivalent O(1)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids.
MgFe2O4 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(1) atoms. Both Mg(1)-O(3) bond lengths are 2.06 Å. All Mg(1)-O(1) bond lengths are 2.29 Å. Fe(1) is bonded to one O(3), two equivalent O(2), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing FeO6 octahedra. The corner-sharing octahedral tilt angles range from 0-57°. The Fe(1)-O(3) bond length is 1.98 Å. Both Fe(1)-O(2) bond lengths are 2.09 Å. There are two shorter (2.04 Å) and one longer (2.11 Å) Fe(1)-O(1) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and three equivalent Fe(1) atoms to form distorted OMg2Fe3 trigonal bipyramids that share corners with five equivalent O(3)Mg2Fe2 tetrahedra, corners with two equivalent O(1)Mg2Fe3 trigonal bipyramids,  an edgeedge with one O(3)Mg2Fe2 tetrahedra, and edges with five equivalent O(1)Mg2Fe3 trigonal bipyramids. In the second O site, O(2) is bonded in a square co-planar geometry to four equivalent Fe(1) atoms. In the third O site, O(3) is bonded to two equivalent Mg(1) and two equivalent Fe(1) atoms to form OMg2Fe2 tetrahedra that share corners with two equivalent O(3)Mg2Fe2 tetrahedra, corners with ten equivalent O(1)Mg2Fe3 trigonal bipyramids, and edges with two equivalent O(1)Mg2Fe3 trigonal bipyramids.