data_[Tb4Mg4Si8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Tb  1.1000  1.7500  0.9815
  Mg  1.3100  1.5000  0.8600
  Si  1.9000  1.1000  0.5400
]
_symmetry_space_group_name_H-M [Pnma]
_cell_length_a [7.9533]
_cell_length_b [3.7700]
_cell_length_c [10.6318]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [62]
_chemical_formula_structural [TbMgSi2]
_chemical_formula_sum '[Tb4 Mg4 Si8]'
_cell_volume [318.7789]
_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
[
  Tb  Tb0  4  0.1282  0.2500  0.1456  1
  Mg  Mg1  4  0.0037  0.7500  0.3912  1
  Si  Si2  4  0.1647  0.2500  0.8184  1
  Si  Si3  4  0.2468  0.7500  0.9442  1
]