data_[Na4Mg12Bi8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Mg  1.3100  1.5000  0.8600
  Bi  2.0200  1.6000  1.0350
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [18.6549]
_cell_length_b [4.6168]
_cell_length_c [10.0091]
_cell_angle_alpha [90.0000]
_cell_angle_beta [121.6202]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [NaMg3Bi2]
_chemical_formula_sum '[Na4 Mg12 Bi8]'
_cell_volume [734.0632]
_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
[
  Na  Na0  4  0.1222  0.0000  0.1423  1.0
  Mg  Mg1  4  0.0344  0.0000  0.6782  1.0
  Mg  Mg2  4  0.0941  0.5000  0.5335  1.0
  Mg  Mg3  4  0.1762  0.5000  0.9037  1.0
  Bi  Bi4  4  0.0050  0.5000  0.1826  1.0
  Bi  Bi5  4  0.2173  0.0000  0.7450  1.0
]