data_[Na2Mg2Nb2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Mg  1.3100  1.5000  0.8600
  Nb  1.6000  1.4500  0.8200
]
_symmetry_space_group_name_H-M [P-1]
_cell_length_a [2.9181]
_cell_length_b [5.7386]
_cell_length_c [8.5500]
_cell_angle_alpha [106.9881]
_cell_angle_beta [92.9422]
_cell_angle_gamma [92.6935]
_symmetry_Int_Tables_number [2]
_chemical_formula_structural [NaMgNb]
_chemical_formula_sum '[Na2 Mg2 Nb2]'
_cell_volume [136.4600]
_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
[
  Na  Na0  1  0.0000  0.0000  0.0000  1
  Na  Na1  1  0.5000  0.5000  0.0000  1
  Mg  Mg2  2  0.1698  0.8508  0.3450  1
  Nb  Nb3  2  0.3461  0.6248  0.6287  1
]