data_RbC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.62
_cell_length_b   4.62
_cell_length_c   7.83
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   RbC2
_chemical_formula_sum   'Rb2 C4'
_cell_volume   166.79
_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
  Rb  Rb0  1  0.0  0.31  0.05  1.0
  Rb  Rb1  1  0.31  0.0  0.78  1.0
  C  C2  1  0.0  0.31  0.11  1.0
  C  C3  1  0.31  0.0  0.73  1.0
  C  C4  1  0.0  0.31  0.37  1.0
  C  C5  1  0.31  0.0  0.46  1.0

data_RbC2
_symmetry_space_group_name_H-M   C2/m
_cell_length_a   6.53
_cell_length_b   6.53
_cell_length_c   7.83
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   12
_chemical_formula_structural   RbC2
_chemical_formula_sum   'Rb4 C8'
_cell_volume   333.58
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-x, -y, -z'
  3  '-x, y, -z'
  4  'x, -y, z'
  5  'x+1/2, y+1/2, z'
  6  '-x+1/2, -y+1/2, -z'
  7  '-x+1/2, y+1/2, -z'
  8  '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
  Rb  Rb0  4  0.15  0.5  0.37  1.0
  C  C1  4  0.15  0.5  0.05  1.0
  C  C2  4  0.15  0.5  0.31  1.0

Rb Rb C C C C