data_[Er8Mg4Se16]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Er  1.2400  1.7500  1.0300
  Mg  1.3100  1.5000  0.8600
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [Pnma]
_cell_length_a [8.1661]
_cell_length_b [7.7162]
_cell_length_c [11.9354]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [62]
_chemical_formula_structural [Er2MgSe4]
_chemical_formula_sum '[Er8 Mg4 Se16]'
_cell_volume [752.0640]
_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
[
  Er  Er0  4  0.0450  0.7500  0.3124  1
  Er  Er1  4  0.0634  0.2500  0.0194  1
  Mg  Mg2  4  0.1833  0.2500  0.4066  1
  Se  Se3  8  0.1254  0.5029  0.8426  1
  Se  Se4  4  0.1097  0.7500  0.5432  1
  Se  Se5  4  0.2234  0.7500  0.1154  1
]