MgFeSbO4 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted MgO4 tetrahedra that share corners with four equivalent Sb(1)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, and  an edgeedge with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-56°. Fe(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with four equivalent Mg(1)O4 tetrahedra, edges with two equivalent Sb(1)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), two equivalent Fe(1), and one Sb(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Sb(1) atoms. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Sb(1) atoms.
MgFeSbO4 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form distorted MgO4 tetrahedra that share corners with four equivalent Sb(1)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra, and  an edgeedge with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 10-56°. Both Mg(1)-O(1) bond lengths are 2.01 Å. Both Mg(1)-O(3) bond lengths are 2.01 Å. Fe(1) is bonded in a 5-coordinate geometry to one O(2) and four equivalent O(1) atoms. The Fe(1)-O(2) bond length is 2.00 Å. All Fe(1)-O(1) bond lengths are 2.20 Å. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form SbO6 octahedra that share corners with four equivalent Mg(1)O4 tetrahedra, edges with two equivalent Sb(1)O6 octahedra, and  an edgeedge with one Mg(1)O4 tetrahedra. Both Sb(1)-O(1) bond lengths are 2.09 Å. Both Sb(1)-O(2) bond lengths are 2.11 Å. Both Sb(1)-O(3) bond lengths are 2.35 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), two equivalent Fe(1), and one Sb(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1) and two equivalent Sb(1) atoms. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Sb(1) atoms.