HoFeNi4 crystallizes in the hexagonal P-6m2 space group. Ho(1) is bonded in a 18-coordinate geometry to three equivalent Fe(1), three equivalent Ni(1), and twelve equivalent Ni(2) atoms. Fe(1) is bonded to three equivalent Ho(1), three equivalent Ni(1), and six equivalent Ni(2) atoms to form distorted FeHo3Ni9 cuboctahedra that share corners with nine equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, corners with twelve equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra, edges with six equivalent Fe(1)Ho3Ni9 cuboctahedra, faces with two equivalent Fe(1)Ho3Ni9 cuboctahedra, faces with three equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, and faces with eighteen equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Ho(1), three equivalent Fe(1), and six equivalent Ni(2) atoms to form distorted NiHo3Fe3Ni6 cuboctahedra that share corners with nine equivalent Fe(1)Ho3Ni9 cuboctahedra, corners with twelve equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra, edges with six equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, faces with two equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, faces with three equivalent Fe(1)Ho3Ni9 cuboctahedra, and faces with eighteen equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra. In the second Ni site, Ni(2) is bonded to four equivalent Ho(1), two equivalent Fe(1), two equivalent Ni(1), and four equivalent Ni(2) atoms to form NiHo4Fe2Ni6 cuboctahedra that share corners with four equivalent Fe(1)Ho3Ni9 cuboctahedra, corners with four equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, corners with sixteen equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra, edges with ten equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra, faces with six equivalent Fe(1)Ho3Ni9 cuboctahedra, faces with six equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, and faces with ten equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra.
HoFeNi4 crystallizes in the hexagonal P-6m2 space group. Ho(1) is bonded in a 18-coordinate geometry to three equivalent Fe(1), three equivalent Ni(1), and twelve equivalent Ni(2) atoms. All Ho(1)-Fe(1) bond lengths are 2.83 Å. All Ho(1)-Ni(1) bond lengths are 2.83 Å. All Ho(1)-Ni(2) bond lengths are 3.15 Å. Fe(1) is bonded to three equivalent Ho(1), three equivalent Ni(1), and six equivalent Ni(2) atoms to form distorted FeHo3Ni9 cuboctahedra that share corners with nine equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, corners with twelve equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra, edges with six equivalent Fe(1)Ho3Ni9 cuboctahedra, faces with two equivalent Fe(1)Ho3Ni9 cuboctahedra, faces with three equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, and faces with eighteen equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra. All Fe(1)-Ni(1) bond lengths are 2.83 Å. All Fe(1)-Ni(2) bond lengths are 2.43 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent Ho(1), three equivalent Fe(1), and six equivalent Ni(2) atoms to form distorted NiHo3Fe3Ni6 cuboctahedra that share corners with nine equivalent Fe(1)Ho3Ni9 cuboctahedra, corners with twelve equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra, edges with six equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, faces with two equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, faces with three equivalent Fe(1)Ho3Ni9 cuboctahedra, and faces with eighteen equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra. All Ni(1)-Ni(2) bond lengths are 2.42 Å. In the second Ni site, Ni(2) is bonded to four equivalent Ho(1), two equivalent Fe(1), two equivalent Ni(1), and four equivalent Ni(2) atoms to form NiHo4Fe2Ni6 cuboctahedra that share corners with four equivalent Fe(1)Ho3Ni9 cuboctahedra, corners with four equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, corners with sixteen equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra, edges with ten equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra, faces with six equivalent Fe(1)Ho3Ni9 cuboctahedra, faces with six equivalent Ni(1)Ho3Fe3Ni6 cuboctahedra, and faces with ten equivalent Ni(2)Ho4Fe2Ni6 cuboctahedra. There are two shorter (2.45 Å) and two longer (2.46 Å) Ni(2)-Ni(2) bond lengths.