MgFe4(CoO4)2 crystallizes in the cubic F-43m space group. Mg(1) is bonded to four equivalent Fe(1) and four equivalent O(1) atoms to form MgFe4O4 tetrahedra that share corners with four equivalent Co(2)O4 tetrahedra. Fe(1) is bonded in a 7-coordinate geometry to one Mg(1), three equivalent O(1), and three equivalent O(2) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a tetrahedral geometry to four equivalent O(2) atoms. In the second Co site, Co(2) is bonded to four equivalent O(1) atoms to form CoO4 tetrahedra that share corners with four equivalent Mg(1)Fe4O4 tetrahedra. There are two inequivalent O sites. In the first O site, O(2) is bonded in a rectangular see-saw-like geometry to three equivalent Fe(1) and one Co(1) atom. In the second O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), three equivalent Fe(1), and one Co(2) atom.
MgFe4(CoO4)2 crystallizes in the cubic F-43m space group. Mg(1) is bonded to four equivalent Fe(1) and four equivalent O(1) atoms to form MgFe4O4 tetrahedra that share corners with four equivalent Co(2)O4 tetrahedra. All Mg(1)-Fe(1) bond lengths are 2.26 Å. All Mg(1)-O(1) bond lengths are 1.86 Å. Fe(1) is bonded in a 7-coordinate geometry to one Mg(1), three equivalent O(1), and three equivalent O(2) atoms. All Fe(1)-O(1) bond lengths are 2.41 Å. All Fe(1)-O(2) bond lengths are 2.03 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a tetrahedral geometry to four equivalent O(2) atoms. All Co(1)-O(2) bond lengths are 2.08 Å. In the second Co site, Co(2) is bonded to four equivalent O(1) atoms to form CoO4 tetrahedra that share corners with four equivalent Mg(1)Fe4O4 tetrahedra. All Co(2)-O(1) bond lengths are 2.06 Å. There are two inequivalent O sites. In the first O site, O(2) is bonded in a rectangular see-saw-like geometry to three equivalent Fe(1) and one Co(1) atom. In the second O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), three equivalent Fe(1), and one Co(2) atom.