HfNbB4 is hexagonal omega structure-derived structured and crystallizes in the hexagonal P6/mmm space group. Hf(1) is bonded to twelve equivalent B(1) atoms to form HfB12 cuboctahedra that share edges with twelve equivalent Nb(1)B12 cuboctahedra, faces with two equivalent Nb(1)B12 cuboctahedra, and faces with six equivalent Hf(1)B12 cuboctahedra. Nb(1) is bonded to twelve equivalent B(1) atoms to form NbB12 cuboctahedra that share edges with twelve equivalent Hf(1)B12 cuboctahedra, faces with two equivalent Hf(1)B12 cuboctahedra, and faces with six equivalent Nb(1)B12 cuboctahedra. B(1) is bonded in a 9-coordinate geometry to three equivalent Hf(1), three equivalent Nb(1), and three equivalent B(1) atoms.
HfNbB4 is hexagonal omega structure-derived structured and crystallizes in the hexagonal P6/mmm space group. Hf(1) is bonded to twelve equivalent B(1) atoms to form HfB12 cuboctahedra that share edges with twelve equivalent Nb(1)B12 cuboctahedra, faces with two equivalent Nb(1)B12 cuboctahedra, and faces with six equivalent Hf(1)B12 cuboctahedra. All Hf(1)-B(1) bond lengths are 2.49 Å. Nb(1) is bonded to twelve equivalent B(1) atoms to form NbB12 cuboctahedra that share edges with twelve equivalent Hf(1)B12 cuboctahedra, faces with two equivalent Hf(1)B12 cuboctahedra, and faces with six equivalent Nb(1)B12 cuboctahedra. All Nb(1)-B(1) bond lengths are 2.47 Å. B(1) is bonded in a 9-coordinate geometry to three equivalent Hf(1), three equivalent Nb(1), and three equivalent B(1) atoms. All B(1)-B(1) bond lengths are 1.80 Å.