MgZn2(NiO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(4), one O(5), one O(6), and one O(8) atom. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(8) atom 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(3)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), one O(5), and one O(7) atom. In the third Ni site, Ni(3) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(7) atom 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 fourth Ni site, Ni(4) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(6), one O(7), and one O(8) atom. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form ZnO4 tetrahedra that share corners with two equivalent Ni(1)O5 square pyramids and corners with two equivalent Ni(3)O5 square pyramids. In the second Zn site, Zn(2) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form distorted ZnO4 tetrahedra that share corners with three equivalent Ni(1)O5 square pyramids and corners with three equivalent Ni(3)O5 square pyramids. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ni(1), one Ni(3), one Ni(4), and one Zn(2) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ni(1), one Ni(2), one Ni(4), and one Zn(2) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ni(1), one Ni(2), one Ni(3), and one Zn(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Ni(2), one Ni(3), and one Zn(1) atom to form a mixture of distorted corner and face-sharing OMgZnNi2 tetrahedra. In the fifth O site, O(5) is bonded to one Mg(1), one Ni(2), one Ni(3), and one Zn(1) atom to form a mixture of distorted corner and face-sharing OMgZnNi2 tetrahedra. In the sixth O site, O(6) is bonded to one Mg(1), one Ni(1), one Ni(4), and one Zn(1) atom to form a mixture of distorted corner and face-sharing OMgZnNi2 tetrahedra. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Ni(2), one Ni(3), one Ni(4), and one Zn(2) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Ni(1), one Ni(4), and one Zn(1) atom to form a mixture of distorted corner and face-sharing OMgZnNi2 tetrahedra.
MgZn2(NiO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(4), one O(5), one O(6), and one O(8) atom. The Mg(1)-O(4) bond length is 1.98 Å. The Mg(1)-O(5) bond length is 1.97 Å. The Mg(1)-O(6) bond length is 1.96 Å. The Mg(1)-O(8) bond length is 1.99 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(8) atom 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(3)O5 square pyramid. The Ni(1)-O(1) bond length is 1.89 Å. The Ni(1)-O(2) bond length is 1.93 Å. The Ni(1)-O(3) bond length is 2.08 Å. The Ni(1)-O(6) bond length is 1.92 Å. The Ni(1)-O(8) bond length is 1.92 Å. In the second Ni site, Ni(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(7) atom. The Ni(2)-O(2) bond length is 2.00 Å. The Ni(2)-O(3) bond length is 2.04 Å. The Ni(2)-O(4) bond length is 2.03 Å. The Ni(2)-O(5) bond length is 2.06 Å. The Ni(2)-O(7) bond length is 2.07 Å. In the third Ni site, Ni(3) is bonded to one O(1), one O(3), one O(4), one O(5), and one O(7) atom 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(3)-O(1) bond length is 2.09 Å. The Ni(3)-O(3) bond length is 1.90 Å. The Ni(3)-O(4) bond length is 1.92 Å. The Ni(3)-O(5) bond length is 1.93 Å. The Ni(3)-O(7) bond length is 1.92 Å. In the fourth Ni site, Ni(4) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(6), one O(7), and one O(8) atom. The Ni(4)-O(1) bond length is 2.02 Å. The Ni(4)-O(2) bond length is 2.07 Å. The Ni(4)-O(6) bond length is 2.04 Å. The Ni(4)-O(7) bond length is 2.02 Å. The Ni(4)-O(8) bond length is 2.05 Å. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form ZnO4 tetrahedra that share corners with two equivalent Ni(1)O5 square pyramids and corners with two equivalent Ni(3)O5 square pyramids. The Zn(1)-O(4) bond length is 2.01 Å. The Zn(1)-O(5) bond length is 2.02 Å. The Zn(1)-O(6) bond length is 1.99 Å. The Zn(1)-O(8) bond length is 2.03 Å. In the second Zn site, Zn(2) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form distorted ZnO4 tetrahedra that share corners with three equivalent Ni(1)O5 square pyramids and corners with three equivalent Ni(3)O5 square pyramids. The Zn(2)-O(1) bond length is 2.24 Å. The Zn(2)-O(2) bond length is 2.09 Å. The Zn(2)-O(3) bond length is 2.19 Å. The Zn(2)-O(7) bond length is 2.10 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ni(1), one Ni(3), one Ni(4), and one Zn(2) atom. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ni(1), one Ni(2), one Ni(4), and one Zn(2) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Ni(1), one Ni(2), one Ni(3), and one Zn(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Ni(2), one Ni(3), and one Zn(1) atom to form a mixture of distorted corner and face-sharing OMgZnNi2 tetrahedra. In the fifth O site, O(5) is bonded to one Mg(1), one Ni(2), one Ni(3), and one Zn(1) atom to form a mixture of distorted corner and face-sharing OMgZnNi2 tetrahedra. In the sixth O site, O(6) is bonded to one Mg(1), one Ni(1), one Ni(4), and one Zn(1) atom to form a mixture of distorted corner and face-sharing OMgZnNi2 tetrahedra. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Ni(2), one Ni(3), one Ni(4), and one Zn(2) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Ni(1), one Ni(4), and one Zn(1) atom to form a mixture of distorted corner and face-sharing OMgZnNi2 tetrahedra.