data_[Pm4Si4Ag8Se16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Pm  1.1300  1.8500  1.1100
  Si  1.9000  1.1000  0.5400
  Ag  1.9300  1.6000  1.0867
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Imma]
_cell_length_a [7.7178]
_cell_length_b [8.3226]
_cell_length_c [11.5481]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [74]
_chemical_formula_structural [PmSi(AgSe2)2]
_chemical_formula_sum '[Pm4 Si4 Ag8 Se16]'
_cell_volume [741.7494]
_cell_formula_units_Z [4]
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
[
  Pm  Pm0  4  0.0000  0.0000  0.0000  1
  Si  Si1  4  0.2500  0.2500  0.2500  1
  Ag  Ag2  4  0.0000  0.0000  0.5000  1
  Ag  Ag3  4  0.2500  0.2500  0.7500  1
  Se  Se4  8  0.0000  0.0252  0.2531  1
  Se  Se5  8  0.2408  0.2500  0.4795  1
]