data_BeB2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.14
_cell_length_b   3.14
_cell_length_c   4.91
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeB2
_chemical_formula_sum   'Be2 B4'
_cell_volume   41.84
_cell_formula_units_Z   2
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
  Be  Be4  1  0.0  0.81  0.23  1.0
  Be  Be5  1  0.57  0.91  0.68  1.0
  B  B0  1  0.0  0.0  0.0  1.0
  B  B1  1  0.0  0.0  0.46  1.0
  B  B2  1  0.57  0.91  0.23  1.0
  B  B3  1  0.0  0.81  0.68  1.0

data_BeB2
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.14
_cell_length_b   3.14
_cell_length_c   4.91
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeB2
_chemical_formula_sum   'Be2 B4'
_cell_volume   41.84
_cell_formula_units_Z   2
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
  Be  Be0  1  0.0  0.81  0.23  1.0
  Be  Be1  1  0.57  0.91  0.68  1.0
  B  B2  1  0.0  0.0  0.0  1.0
  B  B3  1  0.0  0.0  0.46  1.0
  B  B4  1  0.0  0.81  0.68  1.0
  B  B5  1  0.57  0.91  0.23  1.0

Be Be B B B B
BeB2 crystallizes in the triclinic P1 space group. There are two inequivalent Be sites. In the first Be site, Be(1) is bonded in a 4-coordinate geometry to one B(1), one B(2), and two equivalent B(3) atoms. The Be(1)-B(1) bond length is 1.27 Å. The Be(1)-B(2) bond length is 1.27 Å. There is one shorter (1.52 Å) and one longer (1.65 Å) Be(1)-B(3) bond length. In the second Be site, Be(2) is bonded in a 3-coordinate geometry to one B(2) and three equivalent B(4) atoms. The Be(2)-B(2) bond length is 1.67 Å. There are a spread of Be(2)-B(4) bond distances ranging from 1.52-2.46 Å. There are four inequivalent B sites. In the first B site, B(1) is bonded in a distorted single-bond geometry to one Be(1) and one B(4) atom. The B(1)-B(4) bond length is 1.66 Å. In the second B site, B(2) is bonded in a 1-coordinate geometry to one Be(1), one Be(2), and one B(4) atom. The B(2)-B(4) bond length is 1.27 Å. In the third B site, B(3) is bonded in a 2-coordinate geometry to two equivalent Be(1) atoms. In the fourth B site, B(4) is bonded in a 5-coordinate geometry to three equivalent Be(2), one B(1), and one B(2) atom.