data_[Ca4Bi4Se2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Ca  1.0000  1.8000  1.1400
  Bi  2.0200  1.6000  1.0350
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P4/mbm]
_cell_length_a [7.8805]
_cell_length_b [7.8805]
_cell_length_c [5.0895]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [127]
_chemical_formula_structural [Ca2Bi2Se]
_chemical_formula_sum '[Ca4 Bi4 Se2]'
_cell_volume [316.0717]
_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
[
  Ca  Ca0  4  0.1756  0.3244  0.0000  1
  Bi  Bi1  4  0.1315  0.6315  0.5000  1
  Se  Se2  2  0.0000  0.0000  0.0000  1
]