data_Cu2HgSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.76
_cell_length_b   6.76
_cell_length_c   6.76
_cell_angle_alpha   31.12
_cell_angle_beta   31.12
_cell_angle_gamma   31.12
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cu2HgSe
_chemical_formula_sum   'Cu2 Hg1 Se1'
_cell_volume   73.32
_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
  Cu  Cu0  1  0.0  0.0  0.21  1.0
  Cu  Cu1  1  0.0  0.0  0.08  1.0
  Hg  Hg2  1  0.0  0.0  0.65  1.0
  Se  Se3  1  0.0  0.0  0.0  1.0

data_Cu2HgSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   6.28
_cell_length_b   3.63
_cell_length_c   6.76
_cell_angle_alpha   90.0
_cell_angle_beta   108.04
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Cu2HgSe
_chemical_formula_sum   'Cu4 Hg2 Se2'
_cell_volume   146.64
_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
  Cu  Cu0  2  0.0  0.0  0.79  1.0
  Cu  Cu1  2  0.0  0.0  0.92  1.0
  Hg  Hg2  2  0.0  0.0  0.35  1.0
  Se  Se3  2  0.0  0.0  0.0  1.0

Cu Cu Hg Se
Cu Cu Hg Se 0 1 o o o 0 2 o o o 1 3 o o o 1 2 o o - 2 3 o o + 