data_HgB2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.04
_cell_length_b   3.04
_cell_length_c   4.89
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgB2
_chemical_formula_sum   'Hg1 B2'
_cell_volume   39.04
_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
  Hg  Hg2  1  0.0  0.0  0.0  1.0
  B  B0  1  0.0  0.75  0.45  1.0
  B  B1  1  0.52  0.88  0.45  1.0

data_HgB2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.04
_cell_length_b   3.04
_cell_length_c   4.89
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgB2
_chemical_formula_sum   'Hg1 B2'
_cell_volume   39.04
_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
  Hg  Hg0  1  0.0  0.0  0.0  1.0
  B  B1  1  0.0  0.75  0.45  1.0
  B  B2  1  0.52  0.88  0.45  1.0

Hg B B
HgB2 crystallizes in the triclinic P1 space group. Hg(1) is bonded in a 1-coordinate geometry to two equivalent B(1) atoms. There is one shorter (2.30 Å) and one longer (2.81 Å) Hg(1)-B(1) bond length. There are two inequivalent B sites. In the first B site, B(1) is bonded in a 5-coordinate geometry to two equivalent Hg(1) and three equivalent B(2) atoms. There are a spread of B(1)-B(2) bond distances ranging from 1.42-2.31 Å. In the second B site, B(2) is bonded in a distorted bent 150 degrees geometry to three equivalent B(1) atoms.