CaMg5 crystallizes in the orthorhombic Amm2 space group. Ca(1) is bonded to two equivalent Ca(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(5), and four equivalent Mg(2) atoms to form distorted CaCa2Mg10 cuboctahedra that share corners with six equivalent Ca(1)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(4)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with three equivalent Mg(4)Ca2Mg10 cuboctahedra, edges with three equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with eight equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Ca2Mg10 cuboctahedra, faces with two equivalent Mg(5)Ca2Mg10 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, and faces with four equivalent Ca(1)Ca2Mg10 cuboctahedra. There are five 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), two equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with eight equivalent Ca(1)Ca2Mg10 cuboctahedra, faces with two equivalent Ca(1)Ca2Mg10 cuboctahedra, faces with four equivalent Mg(5)Ca2Mg10 cuboctahedra, faces with four equivalent Mg(1)Mg12 cuboctahedra, and faces with six equivalent Mg(4)Ca2Mg10 cuboctahedra. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to four equivalent Ca(1), two equivalent Mg(1), and two equivalent Mg(5) atoms. In the third Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Mg(1), and four equivalent Mg(4) atoms. In the fourth Mg site, Mg(4) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(4), two equivalent Mg(5), and four equivalent Mg(3) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with six equivalent Ca(1)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(4)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with three equivalent Ca(1)Ca2Mg10 cuboctahedra, edges with three equivalent Mg(5)Ca2Mg10 cuboctahedra, faces with two equivalent Ca(1)Ca2Mg10 cuboctahedra, faces with two equivalent Mg(5)Ca2Mg10 cuboctahedra, faces with four equivalent Mg(4)Ca2Mg10 cuboctahedra, and faces with six equivalent Mg(1)Mg12 cuboctahedra. In the fifth Mg site, Mg(5) is bonded to two equivalent Ca(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), and four equivalent Mg(1) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with six equivalent Ca(1)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(4)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with three equivalent Ca(1)Ca2Mg10 cuboctahedra, edges with three equivalent Mg(4)Ca2Mg10 cuboctahedra, edges with four equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Ca(1)Ca2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ca2Mg10 cuboctahedra, faces with four equivalent Mg(5)Ca2Mg10 cuboctahedra, and faces with four equivalent Mg(1)Mg12 cuboctahedra.
CaMg5 crystallizes in the orthorhombic Amm2 space group. Ca(1) is bonded to two equivalent Ca(1), two equivalent Mg(3), two equivalent Mg(4), two equivalent Mg(5), and four equivalent Mg(2) atoms to form distorted CaCa2Mg10 cuboctahedra that share corners with six equivalent Ca(1)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(4)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with three equivalent Mg(4)Ca2Mg10 cuboctahedra, edges with three equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with eight equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Mg(4)Ca2Mg10 cuboctahedra, faces with two equivalent Mg(5)Ca2Mg10 cuboctahedra, faces with two equivalent Mg(1)Mg12 cuboctahedra, and faces with four equivalent Ca(1)Ca2Mg10 cuboctahedra. Both Ca(1)-Ca(1) bond lengths are 3.42 Å. Both Ca(1)-Mg(3) bond lengths are 3.32 Å. Both Ca(1)-Mg(4) bond lengths are 3.47 Å. Both Ca(1)-Mg(5) bond lengths are 3.39 Å. All Ca(1)-Mg(2) bond lengths are 3.31 Å. There are five 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), two equivalent Mg(4), and four equivalent Mg(5) atoms to form MgMg12 cuboctahedra that share corners with six equivalent Mg(1)Mg12 cuboctahedra, edges with four equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with eight equivalent Ca(1)Ca2Mg10 cuboctahedra, faces with two equivalent Ca(1)Ca2Mg10 cuboctahedra, faces with four equivalent Mg(5)Ca2Mg10 cuboctahedra, faces with four equivalent Mg(1)Mg12 cuboctahedra, and faces with six equivalent Mg(4)Ca2Mg10 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 3.42 Å. Both Mg(1)-Mg(2) bond lengths are 3.22 Å. Both Mg(1)-Mg(3) bond lengths are 3.31 Å. Both Mg(1)-Mg(4) bond lengths are 3.21 Å. All Mg(1)-Mg(5) bond lengths are 3.25 Å. In the second Mg site, Mg(2) is bonded in a 4-coordinate geometry to four equivalent Ca(1), two equivalent Mg(1), and two equivalent Mg(5) atoms. Both Mg(2)-Mg(5) bond lengths are 3.23 Å. In the third Mg site, Mg(3) is bonded in a 2-coordinate geometry to two equivalent Ca(1), two equivalent Mg(1), and four equivalent Mg(4) atoms. All Mg(3)-Mg(4) bond lengths are 3.29 Å. In the fourth Mg site, Mg(4) is bonded to two equivalent Ca(1), two equivalent Mg(1), two equivalent Mg(4), two equivalent Mg(5), and four equivalent Mg(3) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with six equivalent Ca(1)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(4)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with three equivalent Ca(1)Ca2Mg10 cuboctahedra, edges with three equivalent Mg(5)Ca2Mg10 cuboctahedra, faces with two equivalent Ca(1)Ca2Mg10 cuboctahedra, faces with two equivalent Mg(5)Ca2Mg10 cuboctahedra, faces with four equivalent Mg(4)Ca2Mg10 cuboctahedra, and faces with six equivalent Mg(1)Mg12 cuboctahedra. Both Mg(4)-Mg(4) bond lengths are 3.42 Å. Both Mg(4)-Mg(5) bond lengths are 3.19 Å. In the fifth Mg site, Mg(5) is bonded to two equivalent Ca(1), two equivalent Mg(2), two equivalent Mg(4), two equivalent Mg(5), and four equivalent Mg(1) atoms to form distorted MgCa2Mg10 cuboctahedra that share corners with six equivalent Ca(1)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(4)Ca2Mg10 cuboctahedra, corners with six equivalent Mg(5)Ca2Mg10 cuboctahedra, edges with three equivalent Ca(1)Ca2Mg10 cuboctahedra, edges with three equivalent Mg(4)Ca2Mg10 cuboctahedra, edges with four equivalent Mg(1)Mg12 cuboctahedra, faces with two equivalent Ca(1)Ca2Mg10 cuboctahedra, faces with two equivalent Mg(4)Ca2Mg10 cuboctahedra, faces with four equivalent Mg(5)Ca2Mg10 cuboctahedra, and faces with four equivalent Mg(1)Mg12 cuboctahedra. Both Mg(5)-Mg(5) bond lengths are 3.42 Å.