Mg2Cd crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), four equivalent Mg(4), and two equivalent Cd(1) atoms to form distorted MgMg10Cd2 cuboctahedra that share corners with six equivalent Mg(1)Mg10Cd2 cuboctahedra, corners with six equivalent Mg(3)Mg6Cd6 cuboctahedra, corners with six equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(3)Mg6Cd6 cuboctahedra, edges with three equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with four equivalent Mg(4)Mg8Cd4 cuboctahedra, edges with eight equivalent Cd(2)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with two equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with two equivalent Cd(2)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with four equivalent Mg(4)Mg8Cd4 cuboctahedra, and faces with six equivalent Cd(1)Mg8Cd4 cuboctahedra. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and four equivalent Cd(2) atoms to form distorted MgMg8Cd4 cuboctahedra that share corners with six equivalent Mg(1)Mg10Cd2 cuboctahedra, corners with six equivalent Mg(3)Mg6Cd6 cuboctahedra, corners with six equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(1)Mg10Cd2 cuboctahedra, edges with three equivalent Mg(3)Mg6Cd6 cuboctahedra, edges with four equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with eight equivalent Cd(1)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with two equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with two equivalent Cd(1)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with four equivalent Cd(2)Mg8Cd4 cuboctahedra, and faces with six equivalent Mg(4)Mg8Cd4 cuboctahedra. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Cd(2), and four equivalent Cd(1) atoms to form distorted MgMg6Cd6 cuboctahedra that share corners with six equivalent Mg(1)Mg10Cd2 cuboctahedra, corners with six equivalent Mg(3)Mg6Cd6 cuboctahedra, corners with six equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(1)Mg10Cd2 cuboctahedra, edges with three equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with four equivalent Cd(1)Mg8Cd4 cuboctahedra, edges with eight equivalent Mg(4)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with two equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(4)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with four equivalent Cd(1)Mg8Cd4 cuboctahedra, and faces with six equivalent Cd(2)Mg8Cd4 cuboctahedra. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(1), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted MgMg8Cd4 cuboctahedra that share corners with six equivalent Mg(4)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(1)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with three equivalent Cd(1)Mg8Cd4 cuboctahedra, edges with three equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with four equivalent Mg(1)Mg10Cd2 cuboctahedra, edges with eight equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with two equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with two equivalent Cd(1)Mg8Cd4 cuboctahedra, faces with two equivalent Cd(2)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with four equivalent Mg(4)Mg8Cd4 cuboctahedra, and faces with six equivalent Mg(2)Mg8Cd4 cuboctahedra. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to two equivalent Mg(1), two equivalent Mg(4), four equivalent Mg(3), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted CdMg8Cd4 cuboctahedra that share corners with six equivalent Mg(4)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(1)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(4)Mg8Cd4 cuboctahedra, edges with three equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with four equivalent Mg(3)Mg6Cd6 cuboctahedra, edges with eight equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(4)Mg8Cd4 cuboctahedra, faces with two equivalent Cd(2)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with four equivalent Cd(1)Mg8Cd4 cuboctahedra, and faces with six equivalent Mg(1)Mg10Cd2 cuboctahedra. In the second Cd site, Cd(2) is bonded to two equivalent Mg(3), two equivalent Mg(4), four equivalent Mg(2), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted CdMg8Cd4 cuboctahedra that share corners with six equivalent Mg(4)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(1)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(4)Mg8Cd4 cuboctahedra, edges with three equivalent Cd(1)Mg8Cd4 cuboctahedra, edges with four equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with eight equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with two equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with two equivalent Mg(4)Mg8Cd4 cuboctahedra, faces with two equivalent Cd(1)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with four equivalent Cd(2)Mg8Cd4 cuboctahedra, and faces with six equivalent Mg(3)Mg6Cd6 cuboctahedra.
Mg2Cd crystallizes in the orthorhombic Amm2 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), four equivalent Mg(4), and two equivalent Cd(1) atoms to form distorted MgMg10Cd2 cuboctahedra that share corners with six equivalent Mg(1)Mg10Cd2 cuboctahedra, corners with six equivalent Mg(3)Mg6Cd6 cuboctahedra, corners with six equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(3)Mg6Cd6 cuboctahedra, edges with three equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with four equivalent Mg(4)Mg8Cd4 cuboctahedra, edges with eight equivalent Cd(2)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with two equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with two equivalent Cd(2)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with four equivalent Mg(4)Mg8Cd4 cuboctahedra, and faces with six equivalent Cd(1)Mg8Cd4 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 3.20 Å. Both Mg(1)-Mg(2) bond lengths are 3.16 Å. Both Mg(1)-Mg(3) bond lengths are 3.11 Å. All Mg(1)-Mg(4) bond lengths are 3.08 Å. Both Mg(1)-Cd(1) bond lengths are 3.05 Å. In the second Mg site, Mg(2) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Mg(4), and four equivalent Cd(2) atoms to form distorted MgMg8Cd4 cuboctahedra that share corners with six equivalent Mg(1)Mg10Cd2 cuboctahedra, corners with six equivalent Mg(3)Mg6Cd6 cuboctahedra, corners with six equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(1)Mg10Cd2 cuboctahedra, edges with three equivalent Mg(3)Mg6Cd6 cuboctahedra, edges with four equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with eight equivalent Cd(1)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with two equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with two equivalent Cd(1)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with four equivalent Cd(2)Mg8Cd4 cuboctahedra, and faces with six equivalent Mg(4)Mg8Cd4 cuboctahedra. Both Mg(2)-Mg(2) bond lengths are 3.20 Å. Both Mg(2)-Mg(3) bond lengths are 3.15 Å. Both Mg(2)-Mg(4) bond lengths are 3.09 Å. All Mg(2)-Cd(2) bond lengths are 3.07 Å. In the third Mg site, Mg(3) is bonded to two equivalent Mg(1), two equivalent Mg(2), two equivalent Mg(3), two equivalent Cd(2), and four equivalent Cd(1) atoms to form distorted MgMg6Cd6 cuboctahedra that share corners with six equivalent Mg(1)Mg10Cd2 cuboctahedra, corners with six equivalent Mg(3)Mg6Cd6 cuboctahedra, corners with six equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(1)Mg10Cd2 cuboctahedra, edges with three equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with four equivalent Cd(1)Mg8Cd4 cuboctahedra, edges with eight equivalent Mg(4)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with two equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(4)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with four equivalent Cd(1)Mg8Cd4 cuboctahedra, and faces with six equivalent Cd(2)Mg8Cd4 cuboctahedra. Both Mg(3)-Mg(3) bond lengths are 3.20 Å. Both Mg(3)-Cd(2) bond lengths are 3.10 Å. All Mg(3)-Cd(1) bond lengths are 3.09 Å. In the fourth Mg site, Mg(4) is bonded to two equivalent Mg(2), two equivalent Mg(4), four equivalent Mg(1), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted MgMg8Cd4 cuboctahedra that share corners with six equivalent Mg(4)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(1)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with three equivalent Cd(1)Mg8Cd4 cuboctahedra, edges with three equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with four equivalent Mg(1)Mg10Cd2 cuboctahedra, edges with eight equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with two equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with two equivalent Cd(1)Mg8Cd4 cuboctahedra, faces with two equivalent Cd(2)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with four equivalent Mg(4)Mg8Cd4 cuboctahedra, and faces with six equivalent Mg(2)Mg8Cd4 cuboctahedra. Both Mg(4)-Mg(4) bond lengths are 3.20 Å. Both Mg(4)-Cd(1) bond lengths are 3.10 Å. Both Mg(4)-Cd(2) bond lengths are 3.13 Å. There are two inequivalent Cd sites. In the first Cd site, Cd(1) is bonded to two equivalent Mg(1), two equivalent Mg(4), four equivalent Mg(3), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted CdMg8Cd4 cuboctahedra that share corners with six equivalent Mg(4)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(1)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(4)Mg8Cd4 cuboctahedra, edges with three equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with four equivalent Mg(3)Mg6Cd6 cuboctahedra, edges with eight equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with two equivalent Mg(4)Mg8Cd4 cuboctahedra, faces with two equivalent Cd(2)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(3)Mg6Cd6 cuboctahedra, faces with four equivalent Cd(1)Mg8Cd4 cuboctahedra, and faces with six equivalent Mg(1)Mg10Cd2 cuboctahedra. Both Cd(1)-Cd(1) bond lengths are 3.20 Å. Both Cd(1)-Cd(2) bond lengths are 3.20 Å. In the second Cd site, Cd(2) is bonded to two equivalent Mg(3), two equivalent Mg(4), four equivalent Mg(2), two equivalent Cd(1), and two equivalent Cd(2) atoms to form distorted CdMg8Cd4 cuboctahedra that share corners with six equivalent Mg(4)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(1)Mg8Cd4 cuboctahedra, corners with six equivalent Cd(2)Mg8Cd4 cuboctahedra, edges with three equivalent Mg(4)Mg8Cd4 cuboctahedra, edges with three equivalent Cd(1)Mg8Cd4 cuboctahedra, edges with four equivalent Mg(2)Mg8Cd4 cuboctahedra, edges with eight equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with two equivalent Mg(1)Mg10Cd2 cuboctahedra, faces with two equivalent Mg(4)Mg8Cd4 cuboctahedra, faces with two equivalent Cd(1)Mg8Cd4 cuboctahedra, faces with four equivalent Mg(2)Mg8Cd4 cuboctahedra, faces with four equivalent Cd(2)Mg8Cd4 cuboctahedra, and faces with six equivalent Mg(3)Mg6Cd6 cuboctahedra. Both Cd(2)-Cd(2) bond lengths are 3.20 Å.