MgFe4(CoO6)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(11), one O(4), and one O(5) atom. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), one O(3), and one O(7) atom. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(10), one O(12), one O(2), one O(3), and one O(6) atom. In the third Fe site, Fe(3) is bonded to one O(1), one O(11), one O(4), one O(5), one O(7), and one O(9) atom to form FeO6 octahedra that share  an edgeedge with one Fe(4)O6 octahedra and  an edgeedge with one Co(2)O6 octahedra. In the fourth Fe site, Fe(4) is bonded to one O(12), one O(2), one O(4), one O(6), one O(8), and one O(9) atom to form FeO6 octahedra that share  an edgeedge with one Fe(3)O6 octahedra and  an edgeedge with one Co(2)O6 octahedra. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(12), one O(2), and one O(9) atom. In the second Co site, Co(2) is bonded to one O(10), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form CoO6 octahedra that share  an edgeedge with one Fe(3)O6 octahedra and  an edgeedge with one Fe(4)O6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Co(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Co(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Co(2) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1), one Fe(3), and one Fe(4) atom. In the fifth O site, O(5) is bonded in a T-shaped geometry to one Mg(1), one Fe(3), and one Co(2) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(4), and one Co(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Co(2) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Fe(4) and one Co(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Fe(3), one Fe(4), and one Co(1) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Co(2) atom. In the eleventh O site, O(11) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Co(1) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Co(1) atom.
MgFe4(CoO6)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(11), one O(4), and one O(5) atom. The Mg(1)-O(1) bond length is 1.98 Å. The Mg(1)-O(11) bond length is 1.98 Å. The Mg(1)-O(4) bond length is 1.91 Å. The Mg(1)-O(5) bond length is 1.93 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), one O(3), and one O(7) atom. The Fe(1)-O(1) bond length is 2.10 Å. The Fe(1)-O(10) bond length is 1.93 Å. The Fe(1)-O(11) bond length is 2.10 Å. The Fe(1)-O(3) bond length is 1.93 Å. The Fe(1)-O(7) bond length is 1.90 Å. In the second Fe site, Fe(2) is bonded in a 5-coordinate geometry to one O(10), one O(12), one O(2), one O(3), and one O(6) atom. The Fe(2)-O(10) bond length is 1.98 Å. The Fe(2)-O(12) bond length is 1.99 Å. The Fe(2)-O(2) bond length is 1.99 Å. The Fe(2)-O(3) bond length is 1.98 Å. The Fe(2)-O(6) bond length is 1.94 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(11), one O(4), one O(5), one O(7), and one O(9) atom to form FeO6 octahedra that share  an edgeedge with one Fe(4)O6 octahedra and  an edgeedge with one Co(2)O6 octahedra. The Fe(3)-O(1) bond length is 2.02 Å. The Fe(3)-O(11) bond length is 2.03 Å. The Fe(3)-O(4) bond length is 1.91 Å. The Fe(3)-O(5) bond length is 1.92 Å. The Fe(3)-O(7) bond length is 1.90 Å. The Fe(3)-O(9) bond length is 1.92 Å. In the fourth Fe site, Fe(4) is bonded to one O(12), one O(2), one O(4), one O(6), one O(8), and one O(9) atom to form FeO6 octahedra that share  an edgeedge with one Fe(3)O6 octahedra and  an edgeedge with one Co(2)O6 octahedra. The Fe(4)-O(12) bond length is 1.97 Å. The Fe(4)-O(2) bond length is 1.97 Å. The Fe(4)-O(4) bond length is 1.88 Å. The Fe(4)-O(6) bond length is 2.00 Å. The Fe(4)-O(8) bond length is 1.86 Å. The Fe(4)-O(9) bond length is 2.32 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a 5-coordinate geometry to one O(1), one O(11), one O(12), one O(2), and one O(9) atom. The Co(1)-O(1) bond length is 2.01 Å. The Co(1)-O(11) bond length is 2.01 Å. The Co(1)-O(12) bond length is 1.90 Å. The Co(1)-O(2) bond length is 1.90 Å. The Co(1)-O(9) bond length is 1.81 Å. In the second Co site, Co(2) is bonded to one O(10), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form CoO6 octahedra that share  an edgeedge with one Fe(3)O6 octahedra and  an edgeedge with one Fe(4)O6 octahedra. The Co(2)-O(10) bond length is 1.92 Å. The Co(2)-O(3) bond length is 1.92 Å. The Co(2)-O(5) bond length is 1.86 Å. The Co(2)-O(6) bond length is 1.91 Å. The Co(2)-O(7) bond length is 1.96 Å. The Co(2)-O(8) bond length is 1.79 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Co(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Co(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Co(2) atom. In the fourth O site, O(4) is bonded in a T-shaped geometry to one Mg(1), one Fe(3), and one Fe(4) atom. In the fifth O site, O(5) is bonded in a T-shaped geometry to one Mg(1), one Fe(3), and one Co(2) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(4), and one Co(2) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(3), and one Co(2) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Fe(4) and one Co(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Fe(3), one Fe(4), and one Co(1) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Fe(1), one Fe(2), and one Co(2) atom. In the eleventh O site, O(11) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Fe(1), one Fe(3), and one Co(1) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(2), one Fe(4), and one Co(1) atom.