Hf2NiAl3 crystallizes in the trigonal R-3m space group. Hf(1) is bonded in a 16-coordinate geometry to four equivalent Hf(1), three equivalent Ni(1), and nine equivalent Al(1) atoms. Ni(1) is bonded to six equivalent Hf(1) and six equivalent Al(1) atoms to form NiHf6Al6 cuboctahedra that share corners with six equivalent Ni(1)Hf6Al6 cuboctahedra, corners with twelve equivalent Al(1)Hf6Al4Ni2 cuboctahedra, edges with six equivalent Ni(1)Hf6Al6 cuboctahedra, and faces with eighteen equivalent Al(1)Hf6Al4Ni2 cuboctahedra. Al(1) is bonded to six equivalent Hf(1), two equivalent Ni(1), and four equivalent Al(1) atoms to form distorted AlHf6Al4Ni2 cuboctahedra that share corners with four equivalent Ni(1)Hf6Al6 cuboctahedra, corners with fourteen equivalent Al(1)Hf6Al4Ni2 cuboctahedra, edges with six equivalent Al(1)Hf6Al4Ni2 cuboctahedra, faces with six equivalent Ni(1)Hf6Al6 cuboctahedra, and faces with twelve equivalent Al(1)Hf6Al4Ni2 cuboctahedra.
Hf2NiAl3 crystallizes in the trigonal R-3m space group. Hf(1) is bonded in a 16-coordinate geometry to four equivalent Hf(1), three equivalent Ni(1), and nine equivalent Al(1) atoms. There is one shorter (3.10 Å) and three longer (3.17 Å) Hf(1)-Hf(1) bond lengths. All Hf(1)-Ni(1) bond lengths are 3.05 Å. There are three shorter (2.95 Å) and six longer (3.03 Å) Hf(1)-Al(1) bond lengths. Ni(1) is bonded to six equivalent Hf(1) and six equivalent Al(1) atoms to form NiHf6Al6 cuboctahedra that share corners with six equivalent Ni(1)Hf6Al6 cuboctahedra, corners with twelve equivalent Al(1)Hf6Al4Ni2 cuboctahedra, edges with six equivalent Ni(1)Hf6Al6 cuboctahedra, and faces with eighteen equivalent Al(1)Hf6Al4Ni2 cuboctahedra. All Ni(1)-Al(1) bond lengths are 2.54 Å. Al(1) is bonded to six equivalent Hf(1), two equivalent Ni(1), and four equivalent Al(1) atoms to form distorted AlHf6Al4Ni2 cuboctahedra that share corners with four equivalent Ni(1)Hf6Al6 cuboctahedra, corners with fourteen equivalent Al(1)Hf6Al4Ni2 cuboctahedra, edges with six equivalent Al(1)Hf6Al4Ni2 cuboctahedra, faces with six equivalent Ni(1)Hf6Al6 cuboctahedra, and faces with twelve equivalent Al(1)Hf6Al4Ni2 cuboctahedra. All Al(1)-Al(1) bond lengths are 2.61 Å.