data_[Na2Ca2Cr2O8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Ca  1.0000  1.8000  1.1400
  Cr  1.6600  1.4000  0.9400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P2_1/m]
_cell_length_a [5.9746]
_cell_length_b [5.8102]
_cell_length_c [6.8656]
_cell_angle_alpha [90.0000]
_cell_angle_beta [91.5580]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [11]
_chemical_formula_structural [NaCaCrO4]
_chemical_formula_sum '[Na2 Ca2 Cr2 O8]'
_cell_volume [238.2395]
_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  2  0.3570  0.7500  0.1368  1.0
  Ca  Ca1  2  0.1807  0.7500  0.5772  1.0
  Cr  Cr2  2  0.3159  0.2500  0.3415  1.0
  O  O3  4  0.1317  0.0167  0.3194  1.0
  O  O4  2  0.4297  0.2500  0.5695  1.0
  O  O5  2  0.4756  0.7500  0.8263  1.0
]