MgZn2(NiO2)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form distorted NiO5 square pyramids that share corners with two equivalent Zn(1)O4 tetrahedra, corners with three equivalent Zn(2)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 square pyramid. In the second Ni site, Ni(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(1) atoms. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form ZnO4 tetrahedra that share corners with four equivalent Ni(1)O5 square pyramids. In the second Zn site, Zn(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form distorted ZnO4 tetrahedra that share corners with six equivalent Ni(1)O5 square pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ni(1), two equivalent Ni(2), and one Zn(2) atom. In the second O site, O(2) is bonded to one Mg(1), one Ni(1), one Ni(2), and one Zn(1) atom to form a mixture of distorted face and corner-sharing OMgZnNi2 tetrahedra. In the third O site, O(3) is bonded to one Mg(1), one Ni(1), one Ni(2), and one Zn(1) atom to form a mixture of distorted face and corner-sharing OMgZnNi2 tetrahedra. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Ni(2), two equivalent Ni(1), and one Zn(2) atom.
MgZn2(NiO2)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(2) and two equivalent O(3) atoms. Both Mg(1)-O(2) bond lengths are 1.97 Å. Both Mg(1)-O(3) bond lengths are 1.99 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), and two equivalent O(4) atoms to form distorted NiO5 square pyramids that share corners with two equivalent Zn(1)O4 tetrahedra, corners with three equivalent Zn(2)O4 tetrahedra, and  an edgeedge with one Ni(1)O5 square pyramid. The Ni(1)-O(1) bond length is 1.93 Å. The Ni(1)-O(2) bond length is 1.92 Å. The Ni(1)-O(3) bond length is 1.93 Å. There is one shorter (1.90 Å) and one longer (2.10 Å) Ni(1)-O(4) bond length. In the second Ni site, Ni(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(1) atoms. The Ni(2)-O(2) bond length is 2.04 Å. The Ni(2)-O(3) bond length is 2.05 Å. The Ni(2)-O(4) bond length is 2.03 Å. There is one shorter (2.00 Å) and one longer (2.08 Å) Ni(2)-O(1) 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(3) atoms to form ZnO4 tetrahedra that share corners with four equivalent Ni(1)O5 square pyramids. Both Zn(1)-O(2) bond lengths are 2.00 Å. Both Zn(1)-O(3) bond lengths are 2.03 Å. In the second Zn site, Zn(2) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form distorted ZnO4 tetrahedra that share corners with six equivalent Ni(1)O5 square pyramids. Both Zn(2)-O(1) bond lengths are 2.09 Å. Both Zn(2)-O(4) bond lengths are 2.22 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ni(1), two equivalent Ni(2), and one Zn(2) atom. In the second O site, O(2) is bonded to one Mg(1), one Ni(1), one Ni(2), and one Zn(1) atom to form a mixture of distorted face and corner-sharing OMgZnNi2 tetrahedra. In the third O site, O(3) is bonded to one Mg(1), one Ni(1), one Ni(2), and one Zn(1) atom to form a mixture of distorted face and corner-sharing OMgZnNi2 tetrahedra. In the fourth O site, O(4) is bonded in a rectangular see-saw-like geometry to one Ni(2), two equivalent Ni(1), and one Zn(2) atom.