CaMg5 crystallizes in the hexagonal P-62m space group. Ca(1) is bonded to six equivalent Mg(1) and six equivalent Mg(2) atoms to form CaMg12 cuboctahedra that share corners with eighteen equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with six equivalent Ca(1)Mg12 cuboctahedra, faces with two equivalent Ca(1)Mg12 cuboctahedra, and faces with six equivalent Mg(2)Ca3Mg9 cuboctahedra. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to two equivalent Ca(1), four equivalent Mg(1), and four equivalent Mg(2) atoms. In the second Mg site, Mg(2) is bonded to three equivalent Ca(1), three equivalent Mg(2), and six equivalent Mg(1) atoms to form distorted MgCa3Mg9 cuboctahedra that share corners with nine equivalent Ca(1)Mg12 cuboctahedra, corners with nine equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with six equivalent Mg(2)Ca3Mg9 cuboctahedra, faces with three equivalent Ca(1)Mg12 cuboctahedra, and faces with five equivalent Mg(2)Ca3Mg9 cuboctahedra.
CaMg5 crystallizes in the hexagonal P-62m space group. Ca(1) is bonded to six equivalent Mg(1) and six equivalent Mg(2) atoms to form CaMg12 cuboctahedra that share corners with eighteen equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with six equivalent Ca(1)Mg12 cuboctahedra, faces with two equivalent Ca(1)Mg12 cuboctahedra, and faces with six equivalent Mg(2)Ca3Mg9 cuboctahedra. All Ca(1)-Mg(1) bond lengths are 3.46 Å. All Ca(1)-Mg(2) bond lengths are 3.37 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded in a 10-coordinate geometry to two equivalent Ca(1), four equivalent Mg(1), and four equivalent Mg(2) atoms. All Mg(1)-Mg(1) bond lengths are 3.12 Å. All Mg(1)-Mg(2) bond lengths are 3.15 Å. In the second Mg site, Mg(2) is bonded to three equivalent Ca(1), three equivalent Mg(2), and six equivalent Mg(1) atoms to form distorted MgCa3Mg9 cuboctahedra that share corners with nine equivalent Ca(1)Mg12 cuboctahedra, corners with nine equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with six equivalent Mg(2)Ca3Mg9 cuboctahedra, faces with three equivalent Ca(1)Mg12 cuboctahedra, and faces with five equivalent Mg(2)Ca3Mg9 cuboctahedra. All Mg(2)-Mg(2) bond lengths are 3.37 Å.