La2Ni2Mg crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one La(2), one La(4), three equivalent La(1), three equivalent La(3), one Ni(1), one Ni(2), and two equivalent Ni(3) atoms to form a mixture of distorted face and corner-sharing MgLa8Ni4 cuboctahedra. In the second Mg site, Mg(2) is bonded to one La(1), one La(3), three equivalent La(2), three equivalent La(4), one Ni(1), one Ni(2), and two equivalent Ni(4) atoms to form a mixture of distorted face and corner-sharing MgLa8Ni4 cuboctahedra. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one Mg(2), three equivalent Mg(1), one Ni(2), one Ni(4), two equivalent Ni(1), and two equivalent Ni(3) atoms. In the second La site, La(2) is bonded in a 6-coordinate geometry to one Mg(1), three equivalent Mg(2), one Ni(1), two equivalent Ni(2), and three equivalent Ni(4) atoms. In the third La site, La(3) is bonded in a 6-coordinate geometry to one Mg(2), three equivalent Mg(1), one Ni(2), two equivalent Ni(1), and three equivalent Ni(3) atoms. In the fourth La site, La(4) is bonded in a 6-coordinate geometry to one Mg(1), three equivalent Mg(2), 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 La(4), two equivalent La(1), three equivalent La(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 La(1), two equivalent La(4), three equivalent La(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 La(2), one La(4), two equivalent La(1), two equivalent La(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 La(1), one La(3), two equivalent La(2), two equivalent La(4), and one Ni(4) atom.
La2Ni2Mg crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one La(2), one La(4), three equivalent La(1), three equivalent La(3), one Ni(1), one Ni(2), and two equivalent Ni(3) atoms to form a mixture of distorted face and corner-sharing MgLa8Ni4 cuboctahedra. The Mg(1)-La(2) bond length is 3.44 Å. The Mg(1)-La(4) bond length is 3.42 Å. There are a spread of Mg(1)-La(1) bond distances ranging from 3.42-3.53 Å. There are two shorter (3.43 Å) and one longer (3.50 Å) Mg(1)-La(3) bond length. The Mg(1)-Ni(1) bond length is 2.93 Å. The Mg(1)-Ni(2) bond length is 3.08 Å. There is one shorter (2.93 Å) and one longer (3.34 Å) Mg(1)-Ni(3) bond length. In the second Mg site, Mg(2) is bonded to one La(1), one La(3), three equivalent La(2), three equivalent La(4), one Ni(1), one Ni(2), and two equivalent Ni(4) atoms to form a mixture of distorted face and corner-sharing MgLa8Ni4 cuboctahedra. The Mg(2)-La(1) bond length is 3.46 Å. The Mg(2)-La(3) bond length is 3.47 Å. There are a spread of Mg(2)-La(2) bond distances ranging from 3.40-3.44 Å. There are a spread of Mg(2)-La(4) bond distances ranging from 3.43-3.49 Å. The Mg(2)-Ni(1) bond length is 3.14 Å. The Mg(2)-Ni(2) bond length is 2.99 Å. There is one shorter (2.95 Å) and one longer (3.00 Å) Mg(2)-Ni(4) bond length. There are four inequivalent La sites. In the first La site, La(1) is bonded in a 6-coordinate geometry to one Mg(2), three equivalent Mg(1), one Ni(2), one Ni(4), two equivalent Ni(1), and two equivalent Ni(3) atoms. The La(1)-Ni(2) bond length is 3.09 Å. The La(1)-Ni(4) bond length is 3.01 Å. There is one shorter (2.94 Å) and one longer (2.99 Å) La(1)-Ni(1) bond length. There is one shorter (2.95 Å) and one longer (3.16 Å) La(1)-Ni(3) bond length. In the second La site, La(2) is bonded in a 6-coordinate geometry to one Mg(1), three equivalent Mg(2), one Ni(1), two equivalent Ni(2), and three equivalent Ni(4) atoms. The La(2)-Ni(1) bond length is 2.99 Å. There is one shorter (2.93 Å) and one longer (3.10 Å) La(2)-Ni(2) bond length. There are a spread of La(2)-Ni(4) bond distances ranging from 2.97-3.08 Å. In the third La site, La(3) is bonded in a 6-coordinate geometry to one Mg(2), three equivalent Mg(1), one Ni(2), two equivalent Ni(1), and three equivalent Ni(3) atoms. The La(3)-Ni(2) bond length is 2.98 Å. There is one shorter (2.97 Å) and one longer (3.04 Å) La(3)-Ni(1) bond length. There are a spread of La(3)-Ni(3) bond distances ranging from 2.89-3.05 Å. In the fourth La site, La(4) is bonded in a 6-coordinate geometry to one Mg(1), three equivalent Mg(2), one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent Ni(4) atoms. The La(4)-Ni(1) bond length is 3.13 Å. The La(4)-Ni(3) bond length is 2.93 Å. There is one shorter (2.96 Å) and one longer (2.97 Å) La(4)-Ni(2) bond length. There is one shorter (2.97 Å) and one longer (3.11 Å) La(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 La(4), two equivalent La(1), three equivalent La(3), and one Ni(1) atom. The Ni(3)-Ni(1) bond length is 2.66 Å. In the second Ni site, Ni(4) is bonded in a 9-coordinate geometry to two equivalent Mg(2), one La(1), two equivalent La(4), three equivalent La(2), and one Ni(2) atom. The Ni(4)-Ni(2) bond length is 2.60 Å. In the third Ni site, Ni(1) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), one La(2), one La(4), two equivalent La(1), two equivalent La(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 La(1), one La(3), two equivalent La(2), two equivalent La(4), and one Ni(4) atom.