data_[Er4Mg2Si4]
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
  Si  1.9000  1.1000  0.5400
]
_symmetry_space_group_name_H-M [P4/mbm]
_cell_length_a [7.1111]
_cell_length_b [7.1111]
_cell_length_c [4.1720]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [127]
_chemical_formula_structural [Er2MgSi2]
_chemical_formula_sum '[Er4 Mg2 Si4]'
_cell_volume [210.9665]
_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
[
  Er  Er0  4  0.1780  0.6780  0.5000  1
  Mg  Mg1  2  0.0000  0.0000  0.0000  1
  Si  Si2  4  0.1189  0.3811  0.0000  1
]