data_[Na8Cr8O28]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Cr  1.6600  1.4000  0.9400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [P-1]
_cell_length_a [7.5034]
_cell_length_b [9.1645]
_cell_length_c [9.7363]
_cell_angle_alpha [76.0096]
_cell_angle_beta [70.4246]
_cell_angle_gamma [70.9701]
_symmetry_Int_Tables_number [2]
_chemical_formula_structural [Na2Cr2O7]
_chemical_formula_sum '[Na8 Cr8 O28]'
_cell_volume [589.7079]
_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
[
  Na  Na0  2  0.0241  0.2636  0.3525  1
  Na  Na1  2  0.0246  0.1027  0.7437  1
  Na  Na2  2  0.4652  0.3904  0.7768  1
  Na  Na3  2  0.4652  0.7835  0.8283  1
  Cr  Cr4  2  0.1668  0.5895  0.0816  1
  Cr  Cr5  2  0.2115  0.1518  0.9885  1
  Cr  Cr6  2  0.2934  0.3749  0.5316  1
  Cr  Cr7  2  0.3250  0.9123  0.4438  1
  O  O8  2  0.0842  0.1238  0.1600  1
  O  O9  2  0.0890  0.3317  0.8970  1
  O  O10  2  0.0947  0.3236  0.5579  1
  O  O11  2  0.1454  0.8625  0.4256  1
  O  O12  2  0.2081  0.4100  0.1624  1
  O  O13  2  0.2268  0.0103  0.9069  1
  O  O14  2  0.2432  0.6943  0.1524  1
  O  O15  2  0.2473  0.5314  0.6028  1
  O  O16  2  0.2870  0.5953  0.9072  1
  O  O17  2  0.2895  0.9165  0.6170  1
  O  O18  2  0.3305  0.0839  0.3494  1
  O  O19  2  0.4058  0.4011  0.3572  1
  O  O20  2  0.4263  0.1693  0.9731  1
  O  O21  2  0.4508  0.2258  0.6272  1
]