data_HgSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.61
_cell_length_b   4.61
_cell_length_c   9.31
_cell_angle_alpha   90.77
_cell_angle_beta   90.77
_cell_angle_gamma   51.09
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgSe
_chemical_formula_sum   'Hg3 Se3'
_cell_volume   153.74
_cell_formula_units_Z   3
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  0.53  0.0  0.63  1.0
  Hg  Hg1  1  0.5  0.0  0.69  1.0
  Hg  Hg2  1  0.22  0.0  0.89  1.0
  Se  Se3  1  0.12  0.0  0.25  1.0
  Se  Se4  1  0.11  0.0  0.29  1.0
  Se  Se5  1  0.01  0.0  0.61  1.0

data_HgSe
_symmetry_space_group_name_H-M   P1
_cell_length_a   3.97
_cell_length_b   4.61
_cell_length_c   9.31
_cell_angle_alpha   90.77
_cell_angle_beta   90.0
_cell_angle_gamma   115.55
_symmetry_Int_Tables_number   1
_chemical_formula_structural   HgSe
_chemical_formula_sum   'Hg3 Se3'
_cell_volume   153.74
_cell_formula_units_Z   3
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  0.47  0.37  1.0
  Hg  Hg1  1  0.0  0.5  0.31  1.0
  Hg  Hg2  1  0.0  0.78  0.11  1.0
  Se  Se3  1  0.0  0.88  0.75  1.0
  Se  Se4  1  0.0  0.89  0.71  1.0
  Se  Se5  1  0.0  0.99  0.39  1.0

Hg Hg Hg Se Se Se
Hg Hg Hg Se Se Se 0 1 o o o 0 2 o o o 0 5 + o o 0 5 o o o 1 2 o o o 1 5 + o o 1 5 o o o 2 5 o o o 3 4 o o o 