CaMg5 crystallizes in the trigonal R32 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 six equivalent Ca(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with six equivalent Ca(1)Mg12 cuboctahedra, edges with twelve equivalent Mg(1)Ca2Mg10 cuboctahedra, faces with eight equivalent Mg(2)Ca3Mg9 cuboctahedra, and faces with twelve equivalent Mg(1)Ca2Mg10 cuboctahedra. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ca(1), four equivalent Mg(2), and six equivalent Mg(1) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with eighteen equivalent Mg(1)Ca2Mg10 cuboctahedra, edges with four equivalent Ca(1)Mg12 cuboctahedra, edges with six equivalent Mg(1)Ca2Mg10 cuboctahedra, edges with eight equivalent Mg(2)Ca3Mg9 cuboctahedra, faces with four equivalent Ca(1)Mg12 cuboctahedra, faces with eight equivalent Mg(1)Ca2Mg10 cuboctahedra, and faces with eight equivalent Mg(2)Ca3Mg9 cuboctahedra. 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 six equivalent Ca(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with six equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with twelve equivalent Mg(1)Ca2Mg10 cuboctahedra, faces with four equivalent Ca(1)Mg12 cuboctahedra, faces with four equivalent Mg(2)Ca3Mg9 cuboctahedra, and faces with twelve equivalent Mg(1)Ca2Mg10 cuboctahedra.
CaMg5 crystallizes in the trigonal R32 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 six equivalent Ca(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with six equivalent Ca(1)Mg12 cuboctahedra, edges with twelve equivalent Mg(1)Ca2Mg10 cuboctahedra, faces with eight equivalent Mg(2)Ca3Mg9 cuboctahedra, and faces with twelve equivalent Mg(1)Ca2Mg10 cuboctahedra. All Ca(1)-Mg(1) bond lengths are 3.39 Å. All Ca(1)-Mg(2) bond lengths are 3.27 Å. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent Ca(1), four equivalent Mg(2), and six equivalent Mg(1) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with eighteen equivalent Mg(1)Ca2Mg10 cuboctahedra, edges with four equivalent Ca(1)Mg12 cuboctahedra, edges with six equivalent Mg(1)Ca2Mg10 cuboctahedra, edges with eight equivalent Mg(2)Ca3Mg9 cuboctahedra, faces with four equivalent Ca(1)Mg12 cuboctahedra, faces with eight equivalent Mg(1)Ca2Mg10 cuboctahedra, and faces with eight equivalent Mg(2)Ca3Mg9 cuboctahedra. There are two shorter (3.36 Å) and two longer (3.40 Å) Mg(1)-Mg(2) bond lengths. There are two shorter (3.22 Å) and four longer (3.29 Å) Mg(1)-Mg(1) bond lengths. 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 six equivalent Ca(1)Mg12 cuboctahedra, corners with twelve equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with six equivalent Mg(2)Ca3Mg9 cuboctahedra, edges with twelve equivalent Mg(1)Ca2Mg10 cuboctahedra, faces with four equivalent Ca(1)Mg12 cuboctahedra, faces with four equivalent Mg(2)Ca3Mg9 cuboctahedra, and faces with twelve equivalent Mg(1)Ca2Mg10 cuboctahedra. All Mg(2)-Mg(2) bond lengths are 3.27 Å.