data_BeHg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.07
_cell_length_b   3.07
_cell_length_c   8.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BeHg
_chemical_formula_sum   'Be2 Hg2'
_cell_volume   66.46
_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  0.53  0.88  0.45  1.0
  Be  Be1  1  0.0  0.77  0.72  1.0
  Hg  Hg2  1  0.53  0.88  0.68  1.0
  Hg  Hg3  1  0.0  0.77  0.49  1.0

data_BeHg
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.07
_cell_length_b   3.07
_cell_length_c   8.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   BeHg
_chemical_formula_sum   'Be2 Hg2'
_cell_volume   66.46
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  2  0.27  0.56  0.37  1.0
  Hg  Hg1  2  0.27  0.56  0.6  1.0

Be Be Hg Hg
Be Be Hg Hg 0 3 o o o 0 3 + o o 0 2 o o o 1 2 - o o 1 2 o o o 1 3 o o o 