data_[Cu4Ge2Se6]
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 [Imm2]
_cell_length_a [4.0419]
_cell_length_b [11.8530]
_cell_length_c [5.5778]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [44]
_chemical_formula_structural [Cu2GeSe3]
_chemical_formula_sum '[Cu4 Ge2 Se6]'
_cell_volume [267.2250]
_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  4  0.0000  0.1673  0.2627  1.0
  Ge  Ge1  2  0.0000  0.5000  0.2334  1.0
  Se  Se2  4  0.0000  0.3292  0.9971  1.0
  Se  Se3  2  0.0000  0.0000  0.0090  1.0
]