MgZn(NiO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra,  a cornercorner with one Zn(1)O5 square pyramid, corners with two equivalent Ni(1)O5 square pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(4)O6 octahedra,  a faceface with one Ni(2)O6 octahedra, and  a faceface with one Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(7), two equivalent O(4), and two equivalent O(5) atoms to form NiO5 square pyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(4)O6 octahedra, edges with two equivalent Ni(1)O5 square pyramids, and edges with two equivalent Zn(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 52-70°. In the second Ni site, Ni(2) is bonded to one O(4), one O(8), two equivalent O(3), and two equivalent O(6) atoms to form distorted NiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra, corners with two equivalent Ni(1)O5 square pyramids, corners with two equivalent Zn(1)O5 square pyramids, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra,  a faceface with one Mg(1)O6 octahedra, and  a faceface with one Zn(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 47-48°. In the third Ni site, Ni(3) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form NiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra, corners with two equivalent Zn(1)O5 square pyramids, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-48°. In the fourth Ni site, Ni(4) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms to form NiO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, corners with two equivalent Zn(1)O5 square pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(4)O6 octahedra,  an edgeedge with one Zn(1)O5 square pyramid, and edges with two equivalent Ni(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 48°. Zn(1) is bonded to one O(4), two equivalent O(6), and two equivalent O(7) atoms to form ZnO5 square pyramids that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Ni(1)O5 square pyramids, edges with two equivalent Zn(1)O5 square pyramids, and  a faceface with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-56°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ni(3), and two equivalent Ni(4) atoms to form OMgNi3 trigonal pyramids that share corners with two equivalent O(7)Zn2Ni3 square pyramids,  a cornercorner with one O(4)MgZnNi3 trigonal bipyramid,  a cornercorner with one O(6)Zn2Ni3 trigonal bipyramid, corners with two equivalent O(1)MgNi3 trigonal pyramids,  an edgeedge with one O(7)Zn2Ni3 square pyramid, edges with two equivalent O(3)Mg2Ni3 trigonal bipyramids, and edges with two equivalent O(2)Mg2Ni2 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Mg(1) and two equivalent Ni(3) atoms to form distorted OMg2Ni2 trigonal pyramids that share corners with two equivalent O(3)Mg2Ni3 trigonal bipyramids, corners with two equivalent O(4)MgZnNi3 trigonal bipyramids, corners with two equivalent O(6)Zn2Ni3 trigonal bipyramids,  an edgeedge with one O(3)Mg2Ni3 trigonal bipyramid, edges with two equivalent O(2)Mg2Ni2 trigonal pyramids, and edges with two equivalent O(1)MgNi3 trigonal pyramids. In the third O site, O(3) is bonded to two equivalent Mg(1), one Ni(4), and two equivalent Ni(2) atoms to form distorted OMg2Ni3 trigonal bipyramids that share corners with two equivalent O(7)Zn2Ni3 square pyramids, corners with two equivalent O(6)Zn2Ni3 trigonal bipyramids, corners with two equivalent O(2)Mg2Ni2 trigonal pyramids,  an edgeedge with one O(6)Zn2Ni3 trigonal bipyramid, edges with two equivalent O(3)Mg2Ni3 trigonal bipyramids, edges with two equivalent O(4)MgZnNi3 trigonal bipyramids,  an edgeedge with one O(2)Mg2Ni2 trigonal pyramid, and edges with two equivalent O(1)MgNi3 trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Ni(2), two equivalent Ni(1), and one Zn(1) atom to form distorted OMgZnNi3 trigonal bipyramids that share corners with two equivalent O(4)MgZnNi3 trigonal bipyramids,  a cornercorner with one O(1)MgNi3 trigonal pyramid, corners with two equivalent O(2)Mg2Ni2 trigonal pyramids, edges with two equivalent O(7)Zn2Ni3 square pyramids, edges with two equivalent O(3)Mg2Ni3 trigonal bipyramids, and edges with two equivalent O(6)Zn2Ni3 trigonal bipyramids. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Ni(4) and two equivalent Ni(1) atoms. In the sixth O site, O(6) is bonded to one Ni(3), two equivalent Ni(2), and two equivalent Zn(1) atoms to form distorted OZn2Ni3 trigonal bipyramids that share corners with two equivalent O(7)Zn2Ni3 square pyramids, corners with two equivalent O(3)Mg2Ni3 trigonal bipyramids,  a cornercorner with one O(1)MgNi3 trigonal pyramid, corners with two equivalent O(2)Mg2Ni2 trigonal pyramids,  an edgeedge with one O(7)Zn2Ni3 square pyramid,  an edgeedge with one O(3)Mg2Ni3 trigonal bipyramid, edges with two equivalent O(4)MgZnNi3 trigonal bipyramids, and edges with two equivalent O(6)Zn2Ni3 trigonal bipyramids. In the seventh O site, O(7) is bonded to one Ni(1), two equivalent Ni(4), and two equivalent Zn(1) atoms to form OZn2Ni3 square pyramids that share corners with two equivalent O(3)Mg2Ni3 trigonal bipyramids, corners with two equivalent O(6)Zn2Ni3 trigonal bipyramids, corners with two equivalent O(1)MgNi3 trigonal pyramids, edges with two equivalent O(7)Zn2Ni3 square pyramids,  an edgeedge with one O(6)Zn2Ni3 trigonal bipyramid, edges with two equivalent O(4)MgZnNi3 trigonal bipyramids, and  an edgeedge with one O(1)MgNi3 trigonal pyramid. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Ni(2) and two equivalent Ni(3) atoms.
MgZn(NiO2)4 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra,  a cornercorner with one Zn(1)O5 square pyramid, corners with two equivalent Ni(1)O5 square pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(4)O6 octahedra,  a faceface with one Ni(2)O6 octahedra, and  a faceface with one Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-47°. The Mg(1)-O(1) bond length is 1.97 Å. The Mg(1)-O(4) bond length is 1.97 Å. Both Mg(1)-O(2) bond lengths are 2.14 Å. Both Mg(1)-O(3) bond lengths are 2.11 Å. There are four inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to one O(7), two equivalent O(4), and two equivalent O(5) atoms to form NiO5 square pyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(4)O6 octahedra, edges with two equivalent Ni(1)O5 square pyramids, and edges with two equivalent Zn(1)O5 square pyramids. The corner-sharing octahedral tilt angles range from 52-70°. The Ni(1)-O(7) bond length is 2.14 Å. Both Ni(1)-O(4) bond lengths are 1.90 Å. Both Ni(1)-O(5) bond lengths are 1.87 Å. In the second Ni site, Ni(2) is bonded to one O(4), one O(8), two equivalent O(3), and two equivalent O(6) atoms to form distorted NiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra, corners with two equivalent Ni(1)O5 square pyramids, corners with two equivalent Zn(1)O5 square pyramids, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra,  a faceface with one Mg(1)O6 octahedra, and  a faceface with one Zn(1)O5 square pyramid. The corner-sharing octahedral tilt angles range from 47-48°. The Ni(2)-O(4) bond length is 2.14 Å. The Ni(2)-O(8) bond length is 1.98 Å. Both Ni(2)-O(3) bond lengths are 2.09 Å. Both Ni(2)-O(6) bond lengths are 2.16 Å. In the third Ni site, Ni(3) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(8) atoms to form NiO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra, corners with two equivalent Zn(1)O5 square pyramids, edges with two equivalent Ni(2)O6 octahedra, edges with two equivalent Ni(3)O6 octahedra, and  a faceface with one Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-48°. The Ni(3)-O(1) bond length is 1.92 Å. The Ni(3)-O(6) bond length is 1.93 Å. Both Ni(3)-O(2) bond lengths are 1.97 Å. Both Ni(3)-O(8) bond lengths are 1.89 Å. In the fourth Ni site, Ni(4) is bonded to one O(3), one O(5), two equivalent O(1), and two equivalent O(7) atoms to form NiO6 octahedra that share corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, corners with two equivalent Zn(1)O5 square pyramids, edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Ni(4)O6 octahedra,  an edgeedge with one Zn(1)O5 square pyramid, and edges with two equivalent Ni(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 48°. The Ni(4)-O(3) bond length is 2.09 Å. The Ni(4)-O(5) bond length is 1.97 Å. Both Ni(4)-O(1) bond lengths are 1.94 Å. There is one shorter (2.12 Å) and one longer (2.13 Å) Ni(4)-O(7) bond length. Zn(1) is bonded to one O(4), two equivalent O(6), and two equivalent O(7) atoms to form ZnO5 square pyramids that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Ni(2)O6 octahedra, corners with two equivalent Ni(3)O6 octahedra, corners with two equivalent Ni(4)O6 octahedra,  an edgeedge with one Ni(4)O6 octahedra, edges with two equivalent Ni(1)O5 square pyramids, edges with two equivalent Zn(1)O5 square pyramids, and  a faceface with one Ni(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 4-56°. The Zn(1)-O(4) bond length is 2.35 Å. Both Zn(1)-O(6) bond lengths are 2.06 Å. Both Zn(1)-O(7) bond lengths are 2.05 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Ni(3), and two equivalent Ni(4) atoms to form OMgNi3 trigonal pyramids that share corners with two equivalent O(7)Zn2Ni3 square pyramids,  a cornercorner with one O(4)MgZnNi3 trigonal bipyramid,  a cornercorner with one O(6)Zn2Ni3 trigonal bipyramid, corners with two equivalent O(1)MgNi3 trigonal pyramids,  an edgeedge with one O(7)Zn2Ni3 square pyramid, edges with two equivalent O(3)Mg2Ni3 trigonal bipyramids, and edges with two equivalent O(2)Mg2Ni2 trigonal pyramids. In the second O site, O(2) is bonded to two equivalent Mg(1) and two equivalent Ni(3) atoms to form distorted OMg2Ni2 trigonal pyramids that share corners with two equivalent O(3)Mg2Ni3 trigonal bipyramids, corners with two equivalent O(4)MgZnNi3 trigonal bipyramids, corners with two equivalent O(6)Zn2Ni3 trigonal bipyramids,  an edgeedge with one O(3)Mg2Ni3 trigonal bipyramid, edges with two equivalent O(2)Mg2Ni2 trigonal pyramids, and edges with two equivalent O(1)MgNi3 trigonal pyramids. In the third O site, O(3) is bonded to two equivalent Mg(1), one Ni(4), and two equivalent Ni(2) atoms to form distorted OMg2Ni3 trigonal bipyramids that share corners with two equivalent O(7)Zn2Ni3 square pyramids, corners with two equivalent O(6)Zn2Ni3 trigonal bipyramids, corners with two equivalent O(2)Mg2Ni2 trigonal pyramids,  an edgeedge with one O(6)Zn2Ni3 trigonal bipyramid, edges with two equivalent O(3)Mg2Ni3 trigonal bipyramids, edges with two equivalent O(4)MgZnNi3 trigonal bipyramids,  an edgeedge with one O(2)Mg2Ni2 trigonal pyramid, and edges with two equivalent O(1)MgNi3 trigonal pyramids. In the fourth O site, O(4) is bonded to one Mg(1), one Ni(2), two equivalent Ni(1), and one Zn(1) atom to form distorted OMgZnNi3 trigonal bipyramids that share corners with two equivalent O(4)MgZnNi3 trigonal bipyramids,  a cornercorner with one O(1)MgNi3 trigonal pyramid, corners with two equivalent O(2)Mg2Ni2 trigonal pyramids, edges with two equivalent O(7)Zn2Ni3 square pyramids, edges with two equivalent O(3)Mg2Ni3 trigonal bipyramids, and edges with two equivalent O(6)Zn2Ni3 trigonal bipyramids. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Ni(4) and two equivalent Ni(1) atoms. In the sixth O site, O(6) is bonded to one Ni(3), two equivalent Ni(2), and two equivalent Zn(1) atoms to form distorted OZn2Ni3 trigonal bipyramids that share corners with two equivalent O(7)Zn2Ni3 square pyramids, corners with two equivalent O(3)Mg2Ni3 trigonal bipyramids,  a cornercorner with one O(1)MgNi3 trigonal pyramid, corners with two equivalent O(2)Mg2Ni2 trigonal pyramids,  an edgeedge with one O(7)Zn2Ni3 square pyramid,  an edgeedge with one O(3)Mg2Ni3 trigonal bipyramid, edges with two equivalent O(4)MgZnNi3 trigonal bipyramids, and edges with two equivalent O(6)Zn2Ni3 trigonal bipyramids. In the seventh O site, O(7) is bonded to one Ni(1), two equivalent Ni(4), and two equivalent Zn(1) atoms to form OZn2Ni3 square pyramids that share corners with two equivalent O(3)Mg2Ni3 trigonal bipyramids, corners with two equivalent O(6)Zn2Ni3 trigonal bipyramids, corners with two equivalent O(1)MgNi3 trigonal pyramids, edges with two equivalent O(7)Zn2Ni3 square pyramids,  an edgeedge with one O(6)Zn2Ni3 trigonal bipyramid, edges with two equivalent O(4)MgZnNi3 trigonal bipyramids, and  an edgeedge with one O(1)MgNi3 trigonal pyramid. In the eighth O site, O(8) is bonded in a distorted trigonal non-coplanar geometry to one Ni(2) and two equivalent Ni(3) atoms.