data_[Na8V4Si4O20]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  V  1.6300  1.3500  0.7775
  Si  1.9000  1.1000  0.5400
  O  3.4400  0.6000  1.2600
]
_symmetry_space_group_name_H-M [Cmc2_1]
_cell_length_a [2.9317]
_cell_length_b [14.2241]
_cell_length_c [10.7393]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [36]
_chemical_formula_structural [Na2VSiO5]
_chemical_formula_sum '[Na8 V4 Si4 O20]'
_cell_volume [447.8407]
_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  4  0.0000  0.0821  0.6553  1
  Na  Na1  4  0.0000  0.1308  0.3120  1
  V  V2  4  0.0000  0.2281  0.0437  1
  Si  Si3  4  0.0000  0.4390  0.4248  1
  O  O4  4  0.0000  0.0393  0.0040  1
  O  O5  4  0.0000  0.2895  0.6589  1
  O  O6  4  0.0000  0.3223  0.4242  1
  O  O7  4  0.0000  0.3443  0.0072  1
  O  O8  4  0.0000  0.4904  0.2938  1
]