data_NaC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.93
_cell_length_b   5.93
_cell_length_c   5.93
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaC2
_chemical_formula_sum   'Na4 C8'
_cell_volume   208.38
_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  Na8  1  0.96  0.0  0.96  1.0
  Na  Na9  1  0.0  0.96  0.96  1.0
  Na  Na10  1  0.0  0.0  0.0  1.0
  Na  Na11  1  0.96  0.96  0.0  1.0
  C  C0  1  0.37  0.33  0.56  1.0
  C  C1  1  0.56  0.6  0.37  1.0
  C  C2  1  0.33  0.56  0.37  1.0
  C  C3  1  0.6  0.37  0.56  1.0
  C  C4  1  0.56  0.37  0.33  1.0
  C  C5  1  0.37  0.56  0.6  1.0
  C  C6  1  0.6  0.6  0.6  1.0
  C  C7  1  0.33  0.33  0.33  1.0

data_NaC2
_symmetry_space_group_name_H-M   R3
_cell_length_a   8.38
_cell_length_b   8.38
_cell_length_c   10.27
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   NaC2
_chemical_formula_sum   'Na12 C24'
_cell_volume   625.15
_cell_formula_units_Z   12
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
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  9  0.02  0.01  0.98  1.0
  Na  Na1  3  0.0  0.0  0.0  1.0
  C  C2  9  0.05  0.14  0.51  1.0
  C  C3  9  0.14  0.09  0.42  1.0
  C  C4  3  0.0  0.0  0.33  1.0
  C  C5  3  0.0  0.0  0.6  1.0

Na Na Na Na C C C C C C C C