data_[Na1As1C1Se2]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Na  0.9300  1.8000  1.1600
  As  2.1800  1.1500  0.6600
  C  2.5500  0.7000  0.3000
  Se  2.5500  1.1500  1.0133
]
_symmetry_space_group_name_H-M [P4/mmm]
_cell_length_a [4.8893]
_cell_length_b [4.8893]
_cell_length_c [4.0485]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [90.0000]
_symmetry_Int_Tables_number [123]
_chemical_formula_structural [NaAsCSe2]
_chemical_formula_sum '[Na1 As1 C1 Se2]'
_cell_volume [96.7800]
_cell_formula_units_Z [1]
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  1  0.5000  0.5000  0.5000  1
  As  As1  1  0.0000  0.0000  0.5000  1
  Se  Se2  2  0.0000  0.5000  0.0000  1
  C  C3  1  0.0000  0.0000  0.0000  1
]