data_[Sr18Ca36Mg3]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Sr  0.9500  2.0000  1.3200
  Ca  1.0000  1.8000  1.1400
  Mg  1.3100  1.5000  0.8600
]
_symmetry_space_group_name_H-M [R-3]
_cell_length_a [13.6095]
_cell_length_b [13.6095]
_cell_length_c [16.2790]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [148]
_chemical_formula_structural [Sr6Ca12Mg]
_chemical_formula_sum '[Sr18 Ca36 Mg3]'
_cell_volume [2611.2306]
_cell_formula_units_Z [3]
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
[
  Sr  Sr0  18  0.0337  0.4386  0.7087  1
  Ca  Ca1  18  0.0401  0.1796  0.8120  1
  Ca  Ca2  18  0.0631  0.8593  0.4087  1
  Mg  Mg3  3  0.0000  0.0000  0.0000  1
]