data_[Cu2Ge6Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Cu  1.9000  1.3500  0.8200
  Ge  2.0100  1.2500  0.7700
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pmn2_1]
_cell_length_a [10.5125]
_cell_length_b [5.8568]
_cell_length_c [5.9390]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [31]
_chemical_formula_structural [CuGe3Se4]
_chemical_formula_sum '[Cu2 Ge6 Se8]'
_cell_volume [365.6646]
_cell_formula_units_Z [2]
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
[
  Cu  Cu0  2  0.0000  0.8162  0.9995  1
  Ge  Ge1  4  0.2499  0.7103  0.4647  1
  Ge  Ge2  2  0.0000  0.2124  0.4563  1
  Se  Se3  4  0.2311  0.7226  0.8995  1
  Se  Se4  2  0.0000  0.2190  0.8977  1
  Se  Se5  2  0.0000  0.7616  0.4027  1
]