Ca(MnAl2)4 crystallizes in the tetragonal I4/mmm space group. Ca(1) is bonded in a 20-coordinate geometry to eight equivalent Mn(1), four equivalent Al(1), and eight equivalent Al(2) atoms. Mn(1) is bonded to two equivalent Ca(1), two equivalent Mn(1), four equivalent Al(1), and four equivalent Al(2) atoms to form distorted MnCa2Mn2Al8 cuboctahedra that share corners with eight equivalent Al(2)Ca2Mn4Al6 cuboctahedra, corners with ten equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, edges with four equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, edges with four equivalent Al(2)Ca2Mn4Al6 cuboctahedra, faces with six equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, and faces with eight equivalent Al(2)Ca2Mn4Al6 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(2) is bonded to two equivalent Ca(1), four equivalent Mn(1), two equivalent Al(2), and four equivalent Al(1) atoms to form distorted AlCa2Mn4Al6 cuboctahedra that share corners with eight equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, corners with ten equivalent Al(2)Ca2Mn4Al6 cuboctahedra, edges with three equivalent Al(2)Ca2Mn4Al6 cuboctahedra, edges with four equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, faces with seven equivalent Al(2)Ca2Mn4Al6 cuboctahedra, and faces with eight equivalent Mn(1)Ca2Mn2Al8 cuboctahedra. In the second Al site, Al(1) is bonded in a 10-coordinate geometry to one Ca(1), four equivalent Mn(1), one Al(1), and four equivalent Al(2) atoms.
Ca(MnAl2)4 crystallizes in the tetragonal I4/mmm space group. Ca(1) is bonded in a 20-coordinate geometry to eight equivalent Mn(1), four equivalent Al(1), and eight equivalent Al(2) atoms. All Ca(1)-Mn(1) bond lengths are 3.36 Å. All Ca(1)-Al(1) bond lengths are 2.92 Å. All Ca(1)-Al(2) bond lengths are 3.28 Å. Mn(1) is bonded to two equivalent Ca(1), two equivalent Mn(1), four equivalent Al(1), and four equivalent Al(2) atoms to form distorted MnCa2Mn2Al8 cuboctahedra that share corners with eight equivalent Al(2)Ca2Mn4Al6 cuboctahedra, corners with ten equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, edges with four equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, edges with four equivalent Al(2)Ca2Mn4Al6 cuboctahedra, faces with six equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, and faces with eight equivalent Al(2)Ca2Mn4Al6 cuboctahedra. Both Mn(1)-Mn(1) bond lengths are 2.59 Å. All Mn(1)-Al(1) bond lengths are 2.65 Å. All Mn(1)-Al(2) bond lengths are 2.55 Å. There are two inequivalent Al sites. In the first Al site, Al(2) is bonded to two equivalent Ca(1), four equivalent Mn(1), two equivalent Al(2), and four equivalent Al(1) atoms to form distorted AlCa2Mn4Al6 cuboctahedra that share corners with eight equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, corners with ten equivalent Al(2)Ca2Mn4Al6 cuboctahedra, edges with three equivalent Al(2)Ca2Mn4Al6 cuboctahedra, edges with four equivalent Mn(1)Ca2Mn2Al8 cuboctahedra, faces with seven equivalent Al(2)Ca2Mn4Al6 cuboctahedra, and faces with eight equivalent Mn(1)Ca2Mn2Al8 cuboctahedra. Both Al(2)-Al(2) bond lengths are 2.83 Å. There are two shorter (2.75 Å) and two longer (2.79 Å) Al(2)-Al(1) bond lengths. In the second Al site, Al(1) is bonded in a 10-coordinate geometry to one Ca(1), four equivalent Mn(1), one Al(1), and four equivalent Al(2) atoms. The Al(1)-Al(1) bond length is 2.92 Å.