data_[Mg12Zn4Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Zn  1.6500  1.3500  0.8800
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cmcm]
_cell_length_a [9.5943]
_cell_length_b [7.7651]
_cell_length_c [7.2214]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [63]
_chemical_formula_structural [Mg3ZnSe2]
_chemical_formula_sum '[Mg12 Zn4 Se8]'
_cell_volume [538.0024]
_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
[
  Mg  Mg0  8  0.1700  0.2715  0.2500  1
  Mg  Mg1  4  0.0000  0.0893  0.7500  1
  Zn  Zn2  4  0.0000  0.4346  0.7500  1
  Se  Se3  8  0.2059  0.0000  0.0000  1
]