Materials Data on HfNbB4 by Materials Project
HfNbB4 is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. Hf4+ is bonded to twelve equivalent B+1.50- atoms to form HfB12 cuboctahedra that share edges with four equivalent NbB12 cuboctahedra, edges with eight equivalent HfB12 cuboctahedra, faces with two equivalent HfB12 cuboctahedra, and faces with six equivalent NbB12 cuboctahedra. All Hf–B bond lengths are 2.48 Å. Nb2+ is bonded to twelve equivalent B+1.50- atoms to form NbB12 cuboctahedra that share edges with four equivalent HfB12 cuboctahedra, edges with eight equivalent NbB12 cuboctahedra, faces with two equivalent NbB12 cuboctahedra, and faces with six equivalent HfB12 cuboctahedra. There are eight shorter (2.48 Å) and four longer (2.49 Å) Nb–B bond lengths. B+1.50- is bonded in a 9-coordinate geometry to three equivalent Hf4+, three equivalent Nb2+, and three equivalent B+1.50- atoms. There is one shorter (1.80 Å) and two longer (1.81 Å) B–B bond length.