data_SnHgSe2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.08
_cell_length_b   5.08
_cell_length_c   3.71
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.87
_symmetry_Int_Tables_number   1
_chemical_formula_structural   SnHgSe2
_chemical_formula_sum   'Sn1 Hg1 Se2'
_cell_volume   95.87
_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
  Sn  Sn3  1  0.0  0.0  0.0  1.0
  Hg  Hg0  1  0.57  0.0  0.0  1.0
  Se  Se1  1  0.78  0.19  0.86  1.0
  Se  Se2  1  0.78  0.81  0.86  1.0

data_SnHgSe2
_symmetry_space_group_name_H-M   Pm
_cell_length_a   3.71
_cell_length_b   5.08
_cell_length_c   5.08
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   6
_chemical_formula_structural   SnHgSe2
_chemical_formula_sum   'Sn1 Hg1 Se2'
_cell_volume   95.88
_cell_formula_units_Z   1
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
  Sn  Sn0  1  0.0  0.0  0.0  1.0
  Hg  Hg1  1  0.0  0.0  0.57  1.0
  Se  Se2  2  0.86  0.19  0.78  1.0

Sn Hg Se Se
Sn Hg Se Se 0 3 - - - 0 2 - o - 1 3 o - - 1 2 o o - 