data_HfSiB2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   2.92
_cell_length_b   2.92
_cell_length_c   5.46
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HfSiB2
_chemical_formula_sum   'Hf1 Si1 B2'
_cell_volume   46.42
_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  Hf2  1  0.46  0.46  0.58  1.0
  Si  Si3  1  0.0  0.0  0.46  1.0
  B  B0  1  0.46  0.46  0.2  1.0
  B  B1  1  0.0  0.0  0.95  1.0

data_HfSiB2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.12
_cell_length_b   4.12
_cell_length_c   5.46
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   HfSiB2
_chemical_formula_sum   'Hf2 Si2 B4'
_cell_volume   92.84
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.46  0.0  0.58  1.0
  Si  Si1  2  0.0  0.0  0.46  1.0
  B  B2  2  0.0  0.0  0.95  1.0
  B  B3  2  0.46  0.0  0.2  1.0

Hf Si B B
HfB2Si crystallizes in the monoclinic Cm space group. Hf(1) is bonded in a 5-coordinate geometry to one B(1), four equivalent B(2), and four equivalent Si(1) atoms. The Hf(1)-B(1) bond length is 2.09 Å. There are a spread of Hf(1)-B(2) bond distances ranging from 2.79-3.03 Å. There are a spread of Hf(1)-Si(1) bond distances ranging from 2.00-2.33 Å. There are two inequivalent B sites. In the first B site, B(1) is bonded in a distorted single-bond geometry to one Hf(1) and one B(2) atom. The B(1)-B(2) bond length is 2.31 Å. In the second B site, B(2) is bonded in a 5-coordinate geometry to four equivalent Hf(1) and one B(1) atom. Si(1) is bonded in a 4-coordinate geometry to four equivalent Hf(1) atoms.