HoFeAl crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 12-coordinate geometry to three equivalent Ho(2), one Fe(3), two equivalent Fe(1), two equivalent Fe(2), three equivalent Al(1), and four equivalent Al(2) atoms. In the second Ho site, Ho(2) is bonded in a 16-coordinate geometry to one Ho(2), three equivalent Ho(1), one Fe(1), two equivalent Fe(3), four equivalent Fe(2), two equivalent Al(2), and three equivalent Al(1) atoms. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Ho(2), four equivalent Ho(1), two equivalent Al(1), and four equivalent Al(2) atoms to form FeHo6Al6 cuboctahedra that share corners with two equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, corners with four equivalent Fe(1)Ho6Al6 cuboctahedra, corners with four equivalent Al(1)Ho6Al2Fe4 cuboctahedra, edges with two equivalent Fe(1)Ho6Al6 cuboctahedra, edges with four equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, faces with six equivalent Al(1)Ho6Al2Fe4 cuboctahedra, and faces with eight equivalent Al(2)Ho6Al4Fe2 cuboctahedra. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to two equivalent Ho(1), four equivalent Ho(2), two equivalent Fe(2), two equivalent Fe(3), and two equivalent Al(1) atoms. In the third Fe site, Fe(3) is bonded to two equivalent Ho(1), four equivalent Ho(2), four equivalent Fe(2), and two equivalent Al(1) atoms to form distorted FeHo6Al2Fe4 cuboctahedra that share corners with two equivalent Fe(1)Ho6Al6 cuboctahedra, corners with four equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, corners with four equivalent Al(1)Ho6Al2Fe4 cuboctahedra, corners with eight equivalent Al(2)Ho6Al4Fe2 cuboctahedra, edges with two equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, edges with four equivalent Fe(1)Ho6Al6 cuboctahedra, faces with four equivalent Al(2)Ho6Al4Fe2 cuboctahedra, and faces with six equivalent Al(1)Ho6Al2Fe4 cuboctahedra. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent Ho(1), three equivalent Ho(2), one Fe(1), one Fe(3), two equivalent Fe(2), and two equivalent Al(2) atoms to form distorted AlHo6Al2Fe4 cuboctahedra that share corners with two equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, corners with two equivalent Fe(1)Ho6Al6 cuboctahedra, corners with four equivalent Al(2)Ho6Al4Fe2 cuboctahedra, edges with six equivalent Al(1)Ho6Al2Fe4 cuboctahedra, faces with two equivalent Al(1)Ho6Al2Fe4 cuboctahedra, faces with three equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, faces with three equivalent Fe(1)Ho6Al6 cuboctahedra, and faces with six equivalent Al(2)Ho6Al4Fe2 cuboctahedra. In the second Al site, Al(2) is bonded to two equivalent Ho(2), four equivalent Ho(1), two equivalent Fe(1), two equivalent Al(1), and two equivalent Al(2) atoms to form distorted AlHo6Al4Fe2 cuboctahedra that share corners with four equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, corners with four equivalent Al(1)Ho6Al2Fe4 cuboctahedra, corners with four equivalent Al(2)Ho6Al4Fe2 cuboctahedra, edges with two equivalent Al(2)Ho6Al4Fe2 cuboctahedra, faces with two equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, faces with four equivalent Fe(1)Ho6Al6 cuboctahedra, faces with four equivalent Al(2)Ho6Al4Fe2 cuboctahedra, and faces with six equivalent Al(1)Ho6Al2Fe4 cuboctahedra.
HoFeAl crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Ho sites. In the first Ho site, Ho(1) is bonded in a 12-coordinate geometry to three equivalent Ho(2), one Fe(3), two equivalent Fe(1), two equivalent Fe(2), three equivalent Al(1), and four equivalent Al(2) atoms. There is one shorter (3.26 Å) and two longer (3.28 Å) Ho(1)-Ho(2) bond lengths. The Ho(1)-Fe(3) bond length is 3.02 Å. Both Ho(1)-Fe(1) bond lengths are 3.18 Å. Both Ho(1)-Fe(2) bond lengths are 3.01 Å. There are two shorter (3.12 Å) and one longer (3.16 Å) Ho(1)-Al(1) bond length. There are two shorter (3.14 Å) and two longer (3.16 Å) Ho(1)-Al(2) bond lengths. In the second Ho site, Ho(2) is bonded in a 16-coordinate geometry to one Ho(2), three equivalent Ho(1), one Fe(1), two equivalent Fe(3), four equivalent Fe(2), two equivalent Al(2), and three equivalent Al(1) atoms. The Ho(2)-Ho(2) bond length is 3.06 Å. The Ho(2)-Fe(1) bond length is 3.19 Å. Both Ho(2)-Fe(3) bond lengths are 3.09 Å. All Ho(2)-Fe(2) bond lengths are 3.06 Å. Both Ho(2)-Al(2) bond lengths are 3.20 Å. There is one shorter (3.03 Å) and two longer (3.16 Å) Ho(2)-Al(1) bond lengths. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent Ho(2), four equivalent Ho(1), two equivalent Al(1), and four equivalent Al(2) atoms to form FeHo6Al6 cuboctahedra that share corners with two equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, corners with four equivalent Fe(1)Ho6Al6 cuboctahedra, corners with four equivalent Al(1)Ho6Al2Fe4 cuboctahedra, edges with two equivalent Fe(1)Ho6Al6 cuboctahedra, edges with four equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, faces with six equivalent Al(1)Ho6Al2Fe4 cuboctahedra, and faces with eight equivalent Al(2)Ho6Al4Fe2 cuboctahedra. Both Fe(1)-Al(1) bond lengths are 2.74 Å. There are two shorter (2.61 Å) and two longer (2.69 Å) Fe(1)-Al(2) bond lengths. In the second Fe site, Fe(2) is bonded in a 12-coordinate geometry to two equivalent Ho(1), four equivalent Ho(2), two equivalent Fe(2), two equivalent Fe(3), and two equivalent Al(1) atoms. There is one shorter (2.48 Å) and one longer (2.89 Å) Fe(2)-Fe(2) bond length. There is one shorter (2.51 Å) and one longer (2.80 Å) Fe(2)-Fe(3) bond length. Both Fe(2)-Al(1) bond lengths are 2.61 Å. In the third Fe site, Fe(3) is bonded to two equivalent Ho(1), four equivalent Ho(2), four equivalent Fe(2), and two equivalent Al(1) atoms to form distorted FeHo6Al2Fe4 cuboctahedra that share corners with two equivalent Fe(1)Ho6Al6 cuboctahedra, corners with four equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, corners with four equivalent Al(1)Ho6Al2Fe4 cuboctahedra, corners with eight equivalent Al(2)Ho6Al4Fe2 cuboctahedra, edges with two equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, edges with four equivalent Fe(1)Ho6Al6 cuboctahedra, faces with four equivalent Al(2)Ho6Al4Fe2 cuboctahedra, and faces with six equivalent Al(1)Ho6Al2Fe4 cuboctahedra. Both Fe(3)-Al(1) bond lengths are 2.61 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to three equivalent Ho(1), three equivalent Ho(2), one Fe(1), one Fe(3), two equivalent Fe(2), and two equivalent Al(2) atoms to form distorted AlHo6Al2Fe4 cuboctahedra that share corners with two equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, corners with two equivalent Fe(1)Ho6Al6 cuboctahedra, corners with four equivalent Al(2)Ho6Al4Fe2 cuboctahedra, edges with six equivalent Al(1)Ho6Al2Fe4 cuboctahedra, faces with two equivalent Al(1)Ho6Al2Fe4 cuboctahedra, faces with three equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, faces with three equivalent Fe(1)Ho6Al6 cuboctahedra, and faces with six equivalent Al(2)Ho6Al4Fe2 cuboctahedra. Both Al(1)-Al(2) bond lengths are 2.81 Å. In the second Al site, Al(2) is bonded to two equivalent Ho(2), four equivalent Ho(1), two equivalent Fe(1), two equivalent Al(1), and two equivalent Al(2) atoms to form distorted AlHo6Al4Fe2 cuboctahedra that share corners with four equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, corners with four equivalent Al(1)Ho6Al2Fe4 cuboctahedra, corners with four equivalent Al(2)Ho6Al4Fe2 cuboctahedra, edges with two equivalent Al(2)Ho6Al4Fe2 cuboctahedra, faces with two equivalent Fe(3)Ho6Al2Fe4 cuboctahedra, faces with four equivalent Fe(1)Ho6Al6 cuboctahedra, faces with four equivalent Al(2)Ho6Al4Fe2 cuboctahedra, and faces with six equivalent Al(1)Ho6Al2Fe4 cuboctahedra. There is one shorter (2.65 Å) and one longer (2.72 Å) Al(2)-Al(2) bond length.