MgCd2(NiO2)4 is Aluminum carbonitride-derived structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(3), 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(5), one O(6), and one O(7) atom to form NiO6 octahedra that share  a cornercorner with one Ni(4)O5 square pyramid, corners with three equivalent Cd(2)O4 tetrahedra, edges with two equivalent Ni(3)O6 octahedra, and  an edgeedge with one Ni(4)O5 square pyramid. In the second Ni site, Ni(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(8) atom. In the third Ni site, Ni(3) is bonded to one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one Ni(4)O5 square pyramid, corners with three equivalent Cd(2)O4 tetrahedra, edges with two equivalent Ni(1)O6 octahedra, and  an edgeedge with one Ni(4)O5 square pyramid. In the fourth Ni site, Ni(4) is bonded to one O(1), one O(4), one O(5), one O(7), and one O(8) atom to form distorted NiO5 square pyramids that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, corners with three equivalent Cd(2)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 69-75°. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(4), and one O(6) atom. In the second Cd site, Cd(2) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form CdO4 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra, corners with three equivalent Ni(3)O6 octahedra, and corners with three equivalent Ni(4)O5 square pyramids. The corner-sharing octahedral tilt angles range from 52-77°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Ni(1), one Ni(2), one Ni(4), and one Cd(1) atom to form OCdNi3 tetrahedra that share  a cornercorner with one O(4)CdNi3 tetrahedra, corners with two equivalent O(6)MgCdNi2 tetrahedra, corners with two equivalent O(8)MgCdNi3 trigonal bipyramids, corners with three equivalent O(5)MgCdNi3 trigonal bipyramids, and  an edgeedge with one O(4)CdNi3 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ni(1), one Ni(2), one Ni(3), and one Cd(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Ni(1), one Ni(3), and one Cd(1) atom. In the fourth O site, O(4) is bonded to one Ni(2), one Ni(3), one Ni(4), and one Cd(1) atom to form distorted OCdNi3 tetrahedra that share  a cornercorner with one O(1)CdNi3 tetrahedra, corners with two equivalent O(6)MgCdNi2 tetrahedra, corners with two equivalent O(5)MgCdNi3 trigonal bipyramids, corners with three equivalent O(8)MgCdNi3 trigonal bipyramids, and  an edgeedge with one O(1)CdNi3 tetrahedra. In the fifth O site, O(5) is bonded to one Mg(1), one Ni(1), one Ni(2), one Ni(4), and one Cd(2) atom to form distorted OMgCdNi3 trigonal bipyramids that share corners with two equivalent O(4)CdNi3 tetrahedra, corners with two equivalent O(6)MgCdNi2 tetrahedra, corners with three equivalent O(1)CdNi3 tetrahedra,  a cornercorner with one O(8)MgCdNi3 trigonal bipyramid, and  a faceface with one O(8)MgCdNi3 trigonal bipyramid. In the sixth O site, O(6) is bonded to one Mg(1), one Ni(1), one Ni(3), and one Cd(1) atom to form distorted OMgCdNi2 tetrahedra that share corners with two equivalent O(1)CdNi3 tetrahedra, corners with two equivalent O(4)CdNi3 tetrahedra, corners with two equivalent O(5)MgCdNi3 trigonal bipyramids, and corners with two equivalent O(8)MgCdNi3 trigonal bipyramids. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Ni(3), one Ni(4), and one Cd(2) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Ni(2), one Ni(3), one Ni(4), and one Cd(2) atom to form distorted OMgCdNi3 trigonal bipyramids that share corners with two equivalent O(1)CdNi3 tetrahedra, corners with two equivalent O(6)MgCdNi2 tetrahedra, corners with three equivalent O(4)CdNi3 tetrahedra,  a cornercorner with one O(5)MgCdNi3 trigonal bipyramid, and  a faceface with one O(5)MgCdNi3 trigonal bipyramid.
MgCd2(NiO2)4 is Aluminum carbonitride-derived structured and crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 4-coordinate geometry to one O(3), one O(5), one O(6), and one O(8) atom. The Mg(1)-O(3) bond length is 1.94 Å. The Mg(1)-O(5) bond length is 2.03 Å. The Mg(1)-O(6) bond length is 1.93 Å. The Mg(1)-O(8) bond length is 2.08 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(5), one O(6), and one O(7) atom to form NiO6 octahedra that share  a cornercorner with one Ni(4)O5 square pyramid, corners with three equivalent Cd(2)O4 tetrahedra, edges with two equivalent Ni(3)O6 octahedra, and  an edgeedge with one Ni(4)O5 square pyramid. The Ni(1)-O(1) bond length is 2.11 Å. The Ni(1)-O(2) bond length is 2.20 Å. The Ni(1)-O(3) bond length is 2.13 Å. The Ni(1)-O(5) bond length is 2.12 Å. The Ni(1)-O(6) bond length is 2.09 Å. The Ni(1)-O(7) bond length is 2.24 Å. In the second Ni site, Ni(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(8) atom. The Ni(2)-O(1) bond length is 1.99 Å. The Ni(2)-O(2) bond length is 1.97 Å. The Ni(2)-O(4) bond length is 1.97 Å. The Ni(2)-O(5) bond length is 2.16 Å. The Ni(2)-O(8) bond length is 2.09 Å. In the third Ni site, Ni(3) is bonded to one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form NiO6 octahedra that share  a cornercorner with one Ni(4)O5 square pyramid, corners with three equivalent Cd(2)O4 tetrahedra, edges with two equivalent Ni(1)O6 octahedra, and  an edgeedge with one Ni(4)O5 square pyramid. The Ni(3)-O(2) bond length is 1.97 Å. The Ni(3)-O(3) bond length is 1.97 Å. The Ni(3)-O(4) bond length is 2.30 Å. The Ni(3)-O(6) bond length is 1.96 Å. The Ni(3)-O(7) bond length is 1.98 Å. The Ni(3)-O(8) bond length is 2.30 Å. In the fourth Ni site, Ni(4) is bonded to one O(1), one O(4), one O(5), one O(7), and one O(8) atom to form distorted NiO5 square pyramids that share  a cornercorner with one Ni(1)O6 octahedra,  a cornercorner with one Ni(3)O6 octahedra, corners with three equivalent Cd(2)O4 tetrahedra,  an edgeedge with one Ni(1)O6 octahedra, and  an edgeedge with one Ni(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 69-75°. The Ni(4)-O(1) bond length is 1.89 Å. The Ni(4)-O(4) bond length is 1.87 Å. The Ni(4)-O(5) bond length is 1.99 Å. The Ni(4)-O(7) bond length is 2.04 Å. The Ni(4)-O(8) bond length is 1.95 Å. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(4), and one O(6) atom. The Cd(1)-O(1) bond length is 2.07 Å. The Cd(1)-O(3) bond length is 2.59 Å. The Cd(1)-O(4) bond length is 2.06 Å. The Cd(1)-O(6) bond length is 2.29 Å. In the second Cd site, Cd(2) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form CdO4 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra, corners with three equivalent Ni(3)O6 octahedra, and corners with three equivalent Ni(4)O5 square pyramids. The corner-sharing octahedral tilt angles range from 52-77°. The Cd(2)-O(2) bond length is 2.24 Å. The Cd(2)-O(5) bond length is 2.22 Å. The Cd(2)-O(7) bond length is 2.19 Å. The Cd(2)-O(8) bond length is 2.17 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Ni(1), one Ni(2), one Ni(4), and one Cd(1) atom to form OCdNi3 tetrahedra that share  a cornercorner with one O(4)CdNi3 tetrahedra, corners with two equivalent O(6)MgCdNi2 tetrahedra, corners with two equivalent O(8)MgCdNi3 trigonal bipyramids, corners with three equivalent O(5)MgCdNi3 trigonal bipyramids, and  an edgeedge with one O(4)CdNi3 tetrahedra. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ni(1), one Ni(2), one Ni(3), and one Cd(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one Ni(1), one Ni(3), and one Cd(1) atom. In the fourth O site, O(4) is bonded to one Ni(2), one Ni(3), one Ni(4), and one Cd(1) atom to form distorted OCdNi3 tetrahedra that share  a cornercorner with one O(1)CdNi3 tetrahedra, corners with two equivalent O(6)MgCdNi2 tetrahedra, corners with two equivalent O(5)MgCdNi3 trigonal bipyramids, corners with three equivalent O(8)MgCdNi3 trigonal bipyramids, and  an edgeedge with one O(1)CdNi3 tetrahedra. In the fifth O site, O(5) is bonded to one Mg(1), one Ni(1), one Ni(2), one Ni(4), and one Cd(2) atom to form distorted OMgCdNi3 trigonal bipyramids that share corners with two equivalent O(4)CdNi3 tetrahedra, corners with two equivalent O(6)MgCdNi2 tetrahedra, corners with three equivalent O(1)CdNi3 tetrahedra,  a cornercorner with one O(8)MgCdNi3 trigonal bipyramid, and  a faceface with one O(8)MgCdNi3 trigonal bipyramid. In the sixth O site, O(6) is bonded to one Mg(1), one Ni(1), one Ni(3), and one Cd(1) atom to form distorted OMgCdNi2 tetrahedra that share corners with two equivalent O(1)CdNi3 tetrahedra, corners with two equivalent O(4)CdNi3 tetrahedra, corners with two equivalent O(5)MgCdNi3 trigonal bipyramids, and corners with two equivalent O(8)MgCdNi3 trigonal bipyramids. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Ni(3), one Ni(4), and one Cd(2) atom. In the eighth O site, O(8) is bonded to one Mg(1), one Ni(2), one Ni(3), one Ni(4), and one Cd(2) atom to form distorted OMgCdNi3 trigonal bipyramids that share corners with two equivalent O(1)CdNi3 tetrahedra, corners with two equivalent O(6)MgCdNi2 tetrahedra, corners with three equivalent O(4)CdNi3 tetrahedra,  a cornercorner with one O(5)MgCdNi3 trigonal bipyramid, and  a faceface with one O(5)MgCdNi3 trigonal bipyramid.