Al9NiCa crystallizes in the hexagonal P6_3/mmc space group. Ca(1) is bonded to twelve equivalent Al(2) atoms to form distorted face-sharing CaAl12 cuboctahedra. Ni(1) is bonded in a 9-coordinate geometry to three equivalent Al(1) and six equivalent Al(2) atoms. There are two inequivalent Al sites. In the first Al site, Al(2) is bonded in a 11-coordinate geometry to two equivalent Ca(1), one Ni(1), four equivalent Al(1), and four equivalent Al(2) atoms. In the second Al site, Al(1) is bonded in a distorted single-bond geometry to one Ni(1) and eight equivalent Al(2) atoms.
Al9NiCa crystallizes in the hexagonal P6_3/mmc space group. Ca(1) is bonded to twelve equivalent Al(2) atoms to form distorted face-sharing CaAl12 cuboctahedra. There are six shorter (3.28 Å) and six longer (3.44 Å) Ca(1)-Al(2) bond lengths. Ni(1) is bonded in a 9-coordinate geometry to three equivalent Al(1) and six equivalent Al(2) atoms. All Ni(1)-Al(1) bond lengths are 2.47 Å. All Ni(1)-Al(2) bond lengths are 2.45 Å. There are two inequivalent Al sites. In the first Al site, Al(2) is bonded in a 11-coordinate geometry to two equivalent Ca(1), one Ni(1), four equivalent Al(1), and four equivalent Al(2) atoms. There are two shorter (2.74 Å) and two longer (2.85 Å) Al(2)-Al(1) bond lengths. There are two shorter (2.73 Å) and two longer (2.81 Å) Al(2)-Al(2) bond lengths. In the second Al site, Al(1) is bonded in a distorted single-bond geometry to one Ni(1) and eight equivalent Al(2) atoms.