data_Hg2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.83
_cell_length_b   9.83
_cell_length_c   9.83
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Hg2Se
_chemical_formula_sum   'Hg16 Se8'
_cell_volume   671.79
_cell_formula_units_Z   8
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  0.74  0.21  0.21  1.0
  Hg  Hg1  1  0.21  0.74  0.21  1.0
  Hg  Hg2  1  0.74  0.74  0.74  1.0
  Hg  Hg3  1  0.21  0.21  0.74  1.0
  Hg  Hg4  1  0.43  0.43  0.27  1.0
  Hg  Hg5  1  0.58  0.43  0.43  1.0
  Hg  Hg6  1  0.43  0.58  0.43  1.0
  Hg  Hg7  1  0.43  0.27  0.43  1.0
  Hg  Hg8  1  0.27  0.43  0.43  1.0
  Hg  Hg9  1  0.43  0.43  0.58  1.0
  Hg  Hg10  1  0.95  0.95  0.11  1.0
  Hg  Hg11  1  0.79  0.95  0.95  1.0
  Hg  Hg12  1  0.95  0.79  0.95  1.0
  Hg  Hg13  1  0.95  0.11  0.95  1.0
  Hg  Hg14  1  0.11  0.95  0.95  1.0
  Hg  Hg15  1  0.95  0.95  0.79  1.0
  Se  Se16  1  0.66  0.66  0.24  1.0
  Se  Se17  1  0.24  0.24  0.24  1.0
  Se  Se18  1  0.66  0.24  0.66  1.0
  Se  Se19  1  0.24  0.66  0.66  1.0
  Se  Se20  1  0.72  0.72  0.14  1.0
  Se  Se21  1  0.14  0.14  0.14  1.0
  Se  Se22  1  0.72  0.14  0.72  1.0
  Se  Se23  1  0.14  0.72  0.72  1.0

data_Hg2Se
_symmetry_space_group_name_H-M   R3m
_cell_length_a   9.83
_cell_length_b   9.83
_cell_length_c   24.08
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Hg2Se
_chemical_formula_sum   'Hg48 Se24'
_cell_volume   2015.38
_cell_formula_units_Z   24
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  9  0.05  0.95  0.52  1.0
  Hg  Hg1  9  0.05  0.1  1.0  1.0
  Hg  Hg2  9  0.1  0.05  0.1  1.0
  Hg  Hg3  9  0.1  0.05  0.63  1.0
  Hg  Hg4  9  0.17  0.35  0.61  1.0
  Hg  Hg5  3  0.0  0.0  0.26  1.0
  Se  Se6  9  0.05  0.53  0.81  1.0
  Se  Se7  9  0.19  0.38  0.14  1.0
  Se  Se8  3  0.0  0.0  0.76  1.0
  Se  Se9  3  0.0  0.0  0.86  1.0

Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Hg Se Se Se Se Se Se Se Se