HoNiAl4 crystallizes in the orthorhombic Cmcm space group. Ho(1) is bonded in a 15-coordinate geometry to two equivalent Ni(1), three equivalent Al(2), four equivalent Al(1), and six equivalent Al(3) atoms. Ni(1) is bonded in a 7-coordinate geometry to two equivalent Ho(1), one Al(2), and six equivalent Al(3) atoms. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted q6 geometry to four equivalent Ho(1), two equivalent Al(3), and four equivalent Al(2) atoms. In the second Al site, Al(2) is bonded in a distorted single-bond geometry to three equivalent Ho(1), one Ni(1), and four equivalent Al(1) atoms. In the third Al site, Al(3) is bonded in a 3-coordinate geometry to three equivalent Ho(1), three equivalent Ni(1), and one Al(1) atom.
HoNiAl4 crystallizes in the orthorhombic Cmcm space group. Ho(1) is bonded in a 15-coordinate geometry to two equivalent Ni(1), three equivalent Al(2), four equivalent Al(1), and six equivalent Al(3) atoms. Both Ho(1)-Ni(1) bond lengths are 3.12 Å. There is one shorter (2.97 Å) and two longer (3.34 Å) Ho(1)-Al(2) bond lengths. All Ho(1)-Al(1) bond lengths are 3.16 Å. There are four shorter (3.03 Å) and two longer (3.22 Å) Ho(1)-Al(3) bond lengths. Ni(1) is bonded in a 7-coordinate geometry to two equivalent Ho(1), one Al(2), and six equivalent Al(3) atoms. The Ni(1)-Al(2) bond length is 2.29 Å. There are two shorter (2.37 Å) and four longer (2.46 Å) Ni(1)-Al(3) bond lengths. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded in a distorted q6 geometry to four equivalent Ho(1), two equivalent Al(3), and four equivalent Al(2) atoms. Both Al(1)-Al(3) bond lengths are 2.91 Å. All Al(1)-Al(2) bond lengths are 2.85 Å. In the second Al site, Al(2) is bonded in a distorted single-bond geometry to three equivalent Ho(1), one Ni(1), and four equivalent Al(1) atoms. In the third Al site, Al(3) is bonded in a 3-coordinate geometry to three equivalent Ho(1), three equivalent Ni(1), and one Al(1) atom.