Nd4Mg3Co2 crystallizes in the monoclinic P2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to one Mg(1), four equivalent Nd(1), four equivalent Nd(2), and one Co(1) atom. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to four equivalent Nd(1), four equivalent Nd(2), and two equivalent Co(1) atoms. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 4-coordinate geometry to two equivalent Mg(2), four equivalent Mg(1), and four equivalent Co(1) atoms. In the second Nd site, Nd(2) is bonded in a distorted L-shaped geometry to two equivalent Mg(2), four equivalent Mg(1), and two equivalent Co(1) atoms. Co(1) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), two equivalent Nd(2), four equivalent Nd(1), and one Co(1) atom.
Nd4Mg3Co2 crystallizes in the monoclinic P2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to one Mg(1), four equivalent Nd(1), four equivalent Nd(2), and one Co(1) atom. The Mg(1)-Mg(1) bond length is 3.16 Å. There are two shorter (3.49 Å) and two longer (3.57 Å) Mg(1)-Nd(1) bond lengths. There are two shorter (3.39 Å) and two longer (3.55 Å) Mg(1)-Nd(2) bond lengths. The Mg(1)-Co(1) bond length is 3.28 Å. In the second Mg site, Mg(2) is bonded in a 10-coordinate geometry to four equivalent Nd(1), four equivalent Nd(2), and two equivalent Co(1) atoms. All Mg(2)-Nd(1) bond lengths are 3.49 Å. All Mg(2)-Nd(2) bond lengths are 3.29 Å. Both Mg(2)-Co(1) bond lengths are 3.15 Å. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 4-coordinate geometry to two equivalent Mg(2), four equivalent Mg(1), and four equivalent Co(1) atoms. All Nd(1)-Co(1) bond lengths are 2.97 Å. In the second Nd site, Nd(2) is bonded in a distorted L-shaped geometry to two equivalent Mg(2), four equivalent Mg(1), and two equivalent Co(1) atoms. Both Nd(2)-Co(1) bond lengths are 2.81 Å. Co(1) is bonded in a 9-coordinate geometry to one Mg(1), one Mg(2), two equivalent Nd(2), four equivalent Nd(1), and one Co(1) atom. The Co(1)-Co(1) bond length is 2.35 Å.