MgZn2(FeO2)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form MgO4 tetrahedra that share corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Zn(2)O4 tetrahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, and edges with two equivalent Zn(2)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(5) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Zn(1)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Zn(2)O4 tetrahedra, corners with four equivalent Fe(2)O5 trigonal bipyramids,  an edgeedge with one Fe(2)O5 trigonal bipyramid, and edges with two equivalent Fe(1)O5 trigonal bipyramids. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(2), and two equivalent O(5) atoms to form FeO5 trigonal bipyramids that share corners with four equivalent Zn(1)O4 tetrahedra,  a cornercorner with one Fe(2)O5 trigonal bipyramid, corners with four equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and edges with two equivalent Fe(2)O5 trigonal bipyramids. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form ZnO4 tetrahedra that share corners with two equivalent Zn(1)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and corners with eight equivalent Fe(2)O5 trigonal bipyramids. In the second Zn site, Zn(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form ZnO4 tetrahedra that share corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Zn(2)O4 tetrahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, and edges with two equivalent Mg(1)O4 tetrahedra. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Fe(1), and one Zn(2) atom to form distorted OMgZnFe2 trigonal pyramids that share corners with two equivalent O(1)MgZnFe2 trigonal pyramids, corners with two equivalent O(2)ZnFe3 trigonal pyramids, and  an edgeedge with one O(1)MgZnFe2 trigonal pyramid. In the second O site, O(2) is bonded to one Fe(1), two equivalent Fe(2), and one Zn(1) atom to form distorted OZnFe3 trigonal pyramids that share corners with four equivalent O(4)Zn2Fe2 tetrahedra, corners with two equivalent O(1)MgZnFe2 trigonal pyramids, and corners with three equivalent O(2)ZnFe3 trigonal pyramids. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Zn(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Fe(2) and two equivalent Zn(1) atoms to form OZn2Fe2 tetrahedra that share corners with two equivalent O(4)Zn2Fe2 tetrahedra and corners with eight equivalent O(2)ZnFe3 trigonal pyramids. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to two equivalent Fe(1) and two equivalent Fe(2) atoms.
MgZn2(FeO2)4 crystallizes in the monoclinic Pm space group. Mg(1) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form MgO4 tetrahedra that share corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Zn(2)O4 tetrahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, and edges with two equivalent Zn(2)O4 tetrahedra. Both Mg(1)-O(1) bond lengths are 1.97 Å. There is one shorter (1.93 Å) and one longer (1.94 Å) Mg(1)-O(3) bond length. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(2), two equivalent O(1), and two equivalent O(5) atoms to form distorted FeO5 trigonal bipyramids that share  a cornercorner with one Zn(1)O4 tetrahedra, corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Zn(2)O4 tetrahedra, corners with four equivalent Fe(2)O5 trigonal bipyramids,  an edgeedge with one Fe(2)O5 trigonal bipyramid, and edges with two equivalent Fe(1)O5 trigonal bipyramids. The Fe(1)-O(2) bond length is 2.21 Å. There is one shorter (2.02 Å) and one longer (2.03 Å) Fe(1)-O(1) bond length. There is one shorter (2.20 Å) and one longer (2.24 Å) Fe(1)-O(5) bond length. In the second Fe site, Fe(2) is bonded to one O(4), two equivalent O(2), and two equivalent O(5) atoms to form FeO5 trigonal bipyramids that share corners with four equivalent Zn(1)O4 tetrahedra,  a cornercorner with one Fe(2)O5 trigonal bipyramid, corners with four equivalent Fe(1)O5 trigonal bipyramids,  an edgeedge with one Fe(1)O5 trigonal bipyramid, and edges with two equivalent Fe(2)O5 trigonal bipyramids. The Fe(2)-O(4) bond length is 2.01 Å. There is one shorter (2.04 Å) and one longer (2.05 Å) Fe(2)-O(2) bond length. There is one shorter (1.97 Å) and one longer (2.02 Å) Fe(2)-O(5) bond length. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form ZnO4 tetrahedra that share corners with two equivalent Zn(1)O4 tetrahedra, corners with two equivalent Fe(1)O5 trigonal bipyramids, and corners with eight equivalent Fe(2)O5 trigonal bipyramids. Both Zn(1)-O(2) bond lengths are 2.04 Å. There is one shorter (2.01 Å) and one longer (2.08 Å) Zn(1)-O(4) bond length. In the second Zn site, Zn(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form ZnO4 tetrahedra that share corners with two equivalent Mg(1)O4 tetrahedra, corners with two equivalent Zn(2)O4 tetrahedra, corners with four equivalent Fe(1)O5 trigonal bipyramids, and edges with two equivalent Mg(1)O4 tetrahedra. Both Zn(2)-O(1) bond lengths are 1.99 Å. There is one shorter (1.96 Å) and one longer (1.99 Å) Zn(2)-O(3) bond length. There are five inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Fe(1), and one Zn(2) atom to form distorted OMgZnFe2 trigonal pyramids that share corners with two equivalent O(1)MgZnFe2 trigonal pyramids, corners with two equivalent O(2)ZnFe3 trigonal pyramids, and  an edgeedge with one O(1)MgZnFe2 trigonal pyramid. In the second O site, O(2) is bonded to one Fe(1), two equivalent Fe(2), and one Zn(1) atom to form distorted OZnFe3 trigonal pyramids that share corners with four equivalent O(4)Zn2Fe2 tetrahedra, corners with two equivalent O(1)MgZnFe2 trigonal pyramids, and corners with three equivalent O(2)ZnFe3 trigonal pyramids. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Mg(1) and two equivalent Zn(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Fe(2) and two equivalent Zn(1) atoms to form OZn2Fe2 tetrahedra that share corners with two equivalent O(4)Zn2Fe2 tetrahedra and corners with eight equivalent O(2)ZnFe3 trigonal pyramids. In the fifth O site, O(5) is bonded in a rectangular see-saw-like geometry to two equivalent Fe(1) and two equivalent Fe(2) atoms.