MgGd2 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded in a body-centered cubic geometry to two equivalent Gd(2) and six equivalent Gd(1) atoms. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 6-coordinate geometry to six equivalent Mg(1) and four equivalent Gd(2) atoms. In the second Gd site, Gd(2) is bonded to two equivalent Mg(1), four equivalent Gd(1), and six equivalent Gd(2) atoms to form a mixture of distorted edge, face, and corner-sharing GdGd10Mg2 cuboctahedra.
MgGd2 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded in a body-centered cubic geometry to two equivalent Gd(2) and six equivalent Gd(1) atoms. Both Mg(1)-Gd(2) bond lengths are 3.34 Å. There are two shorter (3.32 Å) and four longer (3.34 Å) Mg(1)-Gd(1) bond lengths. There are two inequivalent Gd sites. In the first Gd site, Gd(1) is bonded in a 6-coordinate geometry to six equivalent Mg(1) and four equivalent Gd(2) atoms. There are two shorter (3.67 Å) and two longer (3.71 Å) Gd(1)-Gd(2) bond lengths. In the second Gd site, Gd(2) is bonded to two equivalent Mg(1), four equivalent Gd(1), and six equivalent Gd(2) atoms to form a mixture of distorted edge, face, and corner-sharing GdGd10Mg2 cuboctahedra. There are four shorter (3.41 Å) and two longer (3.72 Å) Gd(2)-Gd(2) bond lengths.