data_[Mg6Fe3As3O18]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mg  1.3100  1.5000  0.8600
  Fe  1.8300  1.4000  0.8525
  As  2.1800  1.1500  0.6600
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [R3]
_cell_length_a [5.0913]
_cell_length_b [5.0913]
_cell_length_c [13.5460]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [146]
_chemical_formula_structural [Mg2FeAsO6]
_chemical_formula_sum '[Mg6 Fe3 As3 O18]'
_cell_volume [304.0829]
_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
[
  Mg  Mg0  3  0.0000  0.0000  0.0220  1.0
  Mg  Mg1  3  0.0000  0.0000  0.5281  1.0
  Fe  Fe2  3  0.0000  0.0000  0.8097  1.0
  As  As3  3  0.0000  0.0000  0.3185  1.0
  O  O4  9  0.0205  0.7215  0.4105  1.0
  O  O5  9  0.0430  0.3349  0.9173  1.0
]