The crystal structure described by 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. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfZrB4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.150
_cell_length_b   3.517
_cell_length_c   5.457
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   60.444
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Hf  Hf0  1  0.000  0.000  0.000  1.0
  Zr  Zr1  1  0.500  0.000  0.500  1.0
  B  B2  1  0.000  0.500  0.668  1.0
  B  B3  1  0.500  0.500  0.165  1.0
  B  B4  1  0.500  0.500  0.835  1.0
  B  B5  1  0.000  0.500  0.332  1.0
[/CIF]
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The crystal structure described by 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. is represented by the Crystallographic Information File (CIF) [CIF]
data_HfZrB4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.150
_cell_length_b   3.517
_cell_length_c   5.457
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   60.444
_cell_formula_units_Z   1
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
loop_
 _atom_site_type_symbol
 _atom_site_label
 _atom_site_symmetry_multiplicity
 _atom_site_fract_x
 _atom_site_fract_y
 _atom_site_fract_z
 _atom_site_occupancy
  Hf  Hf0  1  0.000  0.000  0.000  1.0
  Zr  Zr1  1  0.500  0.000  0.500  1.0
  B  B2  1  0.000  0.500  0.668  1.0
  B  B3  1  0.500  0.500  0.165  1.0
  B  B4  1  0.500  0.500  0.835  1.0
  B  B5  1  0.000  0.500  0.332  1.0
[/CIF]
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