data_[Mg4Pb2Se6]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Pb  2.3300  1.8000  1.1225
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Cm]
_cell_length_a [6.7693]
_cell_length_b [12.3255]
_cell_length_c [16.9869]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [8]
_chemical_formula_structural [Mg2PbSe3]
_chemical_formula_sum '[Mg4 Pb2 Se6]'
_cell_volume [1417.2972]
_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  0.0219  0.3364  0.4857  1
  Pb  Pb1  2  0.0736  0.0000  0.5675  1
  Se  Se2  4  0.1608  0.8459  0.4505  1
  Se  Se3  2  0.1478  0.5000  0.5601  1
]