data_[Na4Cu12As8]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  Cu  1.9000  1.3500  0.8200
  As  2.1800  1.1500  0.6600
]
_symmetry_space_group_name_H-M [C2/m]
_cell_length_a [15.2628]
_cell_length_b [3.9790]
_cell_length_c [7.3684]
_cell_angle_alpha [90.0000]
_cell_angle_beta [111.9893]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [12]
_chemical_formula_structural [NaCu3As2]
_chemical_formula_sum '[Na4 Cu12 As8]'
_cell_volume [414.9352]
_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  0.1538  0.0000  0.0648  1.0
  Cu  Cu1  4  0.0458  0.0000  0.3832  1.0
  Cu  Cu2  4  0.0867  0.5000  0.6590  1.0
  Cu  Cu3  4  0.1886  0.5000  0.4532  1.0
  As  As4  4  0.0278  0.5000  0.1843  1.0
  As  As5  4  0.1890  0.0000  0.6869  1.0
]