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 [Cm]
_cell_length_a [5.9162]
_cell_length_b [9.4247]
_cell_length_c [18.2643]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [8]
_chemical_formula_structural [Cu2GeSe3]
_chemical_formula_sum '[Cu4 Ge2 Se6]'
_cell_volume [1018.3873]
_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  0.0959  0.3528  0.5088  1
  Ge  Ge1  2  0.1829  0.0000  0.5190  1
  Se  Se2  4  0.2812  0.2056  0.4282  1
  Se  Se3  2  0.0290  0.5000  0.6069  1
]