Ce2Ni2Mg crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Ni(2), and two equivalent Ni(3) atoms. In the second Mg site, Mg(2) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Ni(2), and two equivalent Ni(4) atoms. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 6-coordinate geometry to one Ni(2), one Ni(4), two equivalent Ni(1), and two equivalent Ni(3) atoms. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to one Ni(1), two equivalent Ni(2), and three equivalent Ni(4) atoms. In the third Ce site, Ce(3) is bonded in a 6-coordinate geometry to one Ni(2), two equivalent Ni(1), and three equivalent Ni(3) atoms. In the fourth Ce site, Ce(4) is bonded in a 6-coordinate geometry to one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent Ni(4) atoms. There are four inequivalent Ni sites. In the first Ni site, Ni(3) is bonded in a 9-coordinate geometry to two equivalent Mg(1), one Ce(4), two equivalent Ce(1), three equivalent Ce(3), and one Ni(1) atom. In the second Ni site, Ni(4) is bonded in a 9-coordinate geometry to two equivalent Mg(2), one Ce(1), two equivalent Ce(4), three equivalent Ce(2), and one Ni(2) atom. In the third Ni site, Ni(1) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), one Ce(2), one Ce(4), two equivalent Ce(1), two equivalent Ce(3), and one Ni(3) atom. In the fourth Ni site, Ni(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), one Ce(1), one Ce(3), two equivalent Ce(2), two equivalent Ce(4), and one Ni(4) atom.
Ce2Ni2Mg crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Ni(2), and two equivalent Ni(3) atoms. The Mg(1)-Ni(1) bond length is 3.00 Å. The Mg(1)-Ni(2) bond length is 2.97 Å. There is one shorter (2.97 Å) and one longer (3.00 Å) Mg(1)-Ni(3) bond length. In the second Mg site, Mg(2) is bonded in a distorted rectangular see-saw-like geometry to one Ni(1), one Ni(2), and two equivalent Ni(4) atoms. The Mg(2)-Ni(1) bond length is 2.91 Å. The Mg(2)-Ni(2) bond length is 3.00 Å. There is one shorter (2.92 Å) and one longer (2.97 Å) Mg(2)-Ni(4) bond length. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 6-coordinate geometry to one Ni(2), one Ni(4), two equivalent Ni(1), and two equivalent Ni(3) atoms. The Ce(1)-Ni(2) bond length is 2.89 Å. The Ce(1)-Ni(4) bond length is 2.90 Å. There is one shorter (2.80 Å) and one longer (2.92 Å) Ce(1)-Ni(1) bond length. There is one shorter (2.81 Å) and one longer (2.90 Å) Ce(1)-Ni(3) bond length. In the second Ce site, Ce(2) is bonded in a 6-coordinate geometry to one Ni(1), two equivalent Ni(2), and three equivalent Ni(4) atoms. The Ce(2)-Ni(1) bond length is 2.82 Å. There is one shorter (2.86 Å) and one longer (2.88 Å) Ce(2)-Ni(2) bond length. There are a spread of Ce(2)-Ni(4) bond distances ranging from 2.82-2.90 Å. In the third Ce site, Ce(3) is bonded in a 6-coordinate geometry to one Ni(2), two equivalent Ni(1), and three equivalent Ni(3) atoms. The Ce(3)-Ni(2) bond length is 2.84 Å. There is one shorter (2.84 Å) and one longer (2.91 Å) Ce(3)-Ni(1) bond length. There is one shorter (2.83 Å) and two longer (2.87 Å) Ce(3)-Ni(3) bond lengths. In the fourth Ce site, Ce(4) is bonded in a 6-coordinate geometry to one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent Ni(4) atoms. The Ce(4)-Ni(1) bond length is 2.91 Å. The Ce(4)-Ni(3) bond length is 2.90 Å. There is one shorter (2.82 Å) and one longer (2.90 Å) Ce(4)-Ni(2) bond length. There is one shorter (2.80 Å) and one longer (2.93 Å) Ce(4)-Ni(4) bond length. There are four inequivalent Ni sites. In the first Ni site, Ni(3) is bonded in a 9-coordinate geometry to two equivalent Mg(1), one Ce(4), two equivalent Ce(1), three equivalent Ce(3), and one Ni(1) atom. The Ni(3)-Ni(1) bond length is 2.80 Å. In the second Ni site, Ni(4) is bonded in a 9-coordinate geometry to two equivalent Mg(2), one Ce(1), two equivalent Ce(4), three equivalent Ce(2), and one Ni(2) atom. The Ni(4)-Ni(2) bond length is 2.75 Å. In the third Ni site, Ni(1) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), one Ce(2), one Ce(4), two equivalent Ce(1), two equivalent Ce(3), and one Ni(3) atom. In the fourth Ni site, Ni(2) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), one Ce(1), one Ce(3), two equivalent Ce(2), two equivalent Ce(4), and one Ni(4) atom.