data_[Rb4Mg2Zn4Se8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Rb  0.8200  2.3500  1.6600
  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 [C2/m]
_cell_length_a [15.9583]
_cell_length_b [4.0638]
_cell_length_c [7.9906]
_cell_angle_alpha [90.0000]
_cell_angle_beta [107.8294]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [Rb2Mg(ZnSe2)2]
_chemical_formula_sum '[Rb4 Mg2 Zn4 Se8]'
_cell_volume [493.3091]
_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
[
  Rb  Rb0  4  0.1253  0.0000  0.5429  1
  Mg  Mg1  2  0.0000  0.0000  0.0000  1
  Zn  Zn2  4  0.1710  0.5000  0.9796  1
  Se  Se3  4  0.0203  0.5000  0.7844  1
  Se  Se4  4  0.2070  0.0000  0.1751  1
]