data_[Na4Cu2C6]
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
  C  2.5500  0.7000  0.3000
]
_symmetry_space_group_name_H-M [P4/mbm]
_cell_length_a [6.0882]
_cell_length_b [6.0882]
_cell_length_c [4.0839]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [127]
_chemical_formula_structural [Na2CuC3]
_chemical_formula_sum '[Na4 Cu2 C6]'
_cell_volume [151.3768]
_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  4  0.1750  0.3250  0.5000  1
  Cu  Cu1  2  0.0000  0.0000  0.0000  1
  C  C2  4  0.1536  0.6536  0.0000  1
  C  C3  2  0.0000  0.5000  0.0000  1
]