data_Si2AgSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.9
_cell_length_b   9.9
_cell_length_c   9.9
_cell_angle_alpha   17.28
_cell_angle_beta   17.28
_cell_angle_gamma   17.28
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Si2AgSe
_chemical_formula_sum   'Si2 Ag1 Se1'
_cell_volume   74.7
_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
  Si  Si2  1  0.0  0.0  0.71  1.0
  Si  Si3  1  0.0  0.0  0.27  1.0
  Ag  Ag0  1  0.0  0.0  0.89  1.0
  Se  Se1  1  0.0  0.0  0.26  1.0

data_Si2AgSe
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.15
_cell_length_b   2.97
_cell_length_c   9.9
_cell_angle_alpha   90.0
_cell_angle_beta   99.99
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Si2AgSe
_chemical_formula_sum   'Si4 Ag2 Se2'
_cell_volume   149.39
_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
  Si  Si0  2  -0.0  0.0  0.73  1.0
  Si  Si1  2  -0.0  0.0  0.29  1.0
  Ag  Ag2  2  -0.0  0.0  0.11  1.0
  Se  Se3  2  -0.0  0.0  0.74  1.0

Si Si Ag Se
Si Si Ag Se 0 2 o o o 1 3 o o o 