ZrB2(HfB2) is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Pmmm space group. Hf(1) is bonded to four equivalent B(1) and eight equivalent B(2) atoms to form HfB12 cuboctahedra that share edges with four equivalent Hf(1)B12 cuboctahedra, edges with eight equivalent Zr(1)B12 cuboctahedra, faces with four equivalent Hf(1)B12 cuboctahedra, and faces with four equivalent Zr(1)B12 cuboctahedra. Zr(1) is bonded to four equivalent B(2) and eight equivalent B(1) atoms to form ZrB12 cuboctahedra that share edges with four equivalent Zr(1)B12 cuboctahedra, edges with eight equivalent Hf(1)B12 cuboctahedra, faces with four equivalent Hf(1)B12 cuboctahedra, and faces with four equivalent Zr(1)B12 cuboctahedra. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Hf(1), four equivalent Zr(1), one B(1), and two equivalent B(2) atoms. In the second B site, B(2) is bonded in a 9-coordinate geometry to four equivalent Hf(1), two equivalent Zr(1), one B(2), and two equivalent B(1) atoms.
ZrB2(HfB2) is hexagonal omega structure-derived structured and crystallizes in the orthorhombic Pmmm space group. Hf(1) is bonded to four equivalent B(1) and eight equivalent B(2) atoms to form HfB12 cuboctahedra that share edges with four equivalent Hf(1)B12 cuboctahedra, edges with eight equivalent Zr(1)B12 cuboctahedra, faces with four equivalent Hf(1)B12 cuboctahedra, and faces with four equivalent Zr(1)B12 cuboctahedra. All Hf(1)-B(1) bond lengths are 2.52 Å. All Hf(1)-B(2) bond lengths are 2.53 Å. Zr(1) is bonded to four equivalent B(2) and eight equivalent B(1) atoms to form ZrB12 cuboctahedra that share edges with four equivalent Zr(1)B12 cuboctahedra, edges with eight equivalent Hf(1)B12 cuboctahedra, faces with four equivalent Hf(1)B12 cuboctahedra, and faces with four equivalent Zr(1)B12 cuboctahedra. All Zr(1)-B(2) bond lengths are 2.54 Å. All Zr(1)-B(1) bond lengths are 2.53 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 9-coordinate geometry to two equivalent Hf(1), four equivalent Zr(1), one B(1), and two equivalent B(2) atoms. The B(1)-B(1) bond length is 1.84 Å. Both B(1)-B(2) bond lengths are 1.82 Å. In the second B site, B(2) is bonded in a 9-coordinate geometry to four equivalent Hf(1), two equivalent Zr(1), one B(2), and two equivalent B(1) atoms. The B(2)-B(2) bond length is 1.80 Å.