data_NaC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.33
_cell_length_b   4.33
_cell_length_c   11.22
_cell_angle_alpha   90.49
_cell_angle_beta   90.49
_cell_angle_gamma   59.58
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NaC2
_chemical_formula_sum   'Na3 C6'
_cell_volume   181.72
_cell_formula_units_Z   3
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  Na6  1  0.0  0.0  0.0  1.0
  Na  Na7  1  0.95  0.0  0.05  1.0
  Na  Na8  1  0.46  0.0  0.17  1.0
  C  C0  1  0.46  0.0  0.25  1.0
  C  C1  1  0.95  0.0  0.97  1.0
  C  C2  1  0.93  0.0  0.52  1.0
  C  C3  1  0.48  0.0  0.7  1.0
  C  C4  1  0.94  0.0  0.82  1.0
  C  C5  1  0.47  0.0  0.41  1.0

data_NaC2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.33
_cell_length_b   7.47
_cell_length_c   11.22
_cell_angle_alpha   90.0
_cell_angle_beta   90.49
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   NaC2
_chemical_formula_sum   'Na6 C12'
_cell_volume   363.46
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'x, -y, z'
  3  'x+1/2, y+1/2, z'
  4  'x+1/2, -y+1/2, 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  2  0.0  0.0  0.0  1.0
  Na  Na1  2  0.04  0.5  0.83  1.0
  Na  Na2  2  0.05  0.0  0.95  1.0
  C  C3  2  0.02  0.5  0.3  1.0
  C  C4  2  0.03  0.5  0.59  1.0
  C  C5  2  0.04  0.5  0.75  1.0
  C  C6  2  0.05  0.0  0.03  1.0
  C  C7  2  0.06  0.0  0.18  1.0
  C  C8  2  0.07  0.0  0.48  1.0

Na Na Na C C C C C C