data_[Mg4Si4Se12]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Si  1.9000  1.1000  0.5400
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P2_1/c]
_cell_length_a [6.8233]
_cell_length_b [7.0743]
_cell_length_c [12.3220]
_cell_angle_alpha [90.0000]
_cell_angle_beta [114.2284]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [14]
_chemical_formula_structural [MgSiSe3]
_chemical_formula_sum '[Mg4 Si4 Se12]'
_cell_volume [542.3916]
_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
[
  Mg  Mg0  4  0.2520  0.6456  0.2733  1.0
  Si  Si1  4  0.3672  0.1010  0.3784  1.0
  Se  Se2  4  0.1190  0.1726  0.8562  1.0
  Se  Se3  4  0.2843  0.6586  0.9734  1.0
  Se  Se4  4  0.3859  0.5074  0.7104  1.0
]