data_[Mg16Se24]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Fdd2]
_cell_length_a [8.8887]
_cell_length_b [12.6271]
_cell_length_c [8.1737]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [43]
_chemical_formula_structural [Mg2Se3]
_chemical_formula_sum '[Mg16 Se24]'
_cell_volume [917.4021]
_cell_formula_units_Z [8]
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  16  0.0153  0.2012  0.7974  1
  Se  Se1  16  0.0757  0.1294  0.4954  1
  Se  Se2  8  0.0000  0.0000  0.9145  1
]