data_[Mg4Cu2Ge2Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  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 [I-42m]
_cell_length_a [5.9309]
_cell_length_b [5.9309]
_cell_length_c [11.7243]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [121]
_chemical_formula_structural [Mg2CuGeSe4]
_chemical_formula_sum '[Mg4 Cu2 Ge2 Se8]'
_cell_volume [412.4108]
_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
[
  Mg  Mg0  4  0.0000  0.5000  0.2500  1
  Cu  Cu1  2  0.0000  0.0000  0.5000  1
  Ge  Ge2  2  0.0000  0.0000  0.0000  1
  Se  Se3  8  0.2388  0.2388  0.6196  1
]