data_BiC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.47
_cell_length_b   5.47
_cell_length_c   3.63
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   BiC2
_chemical_formula_sum   'Bi2 C4'
_cell_volume   108.56
_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
  Bi  Bi0  1  0.0  0.0  0.0  1.0
  Bi  Bi1  1  0.74  0.74  0.81  1.0
  C  C2  1  0.67  0.67  0.0  1.0
  C  C3  1  0.8  0.8  0.0  1.0
  C  C4  1  0.06  0.41  0.81  1.0
  C  C5  1  0.41  0.06  0.81  1.0

data_BiC2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   7.74
_cell_length_b   7.74
_cell_length_c   3.63
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   BiC2
_chemical_formula_sum   'Bi4 C8'
_cell_volume   217.11
_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+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
  Bi  Bi0  2  0.0  0.0  0.0  1.0
  Bi  Bi1  2  0.24  0.5  0.81  1.0
  C  C2  4  0.24  0.17  0.81  1.0
  C  C3  2  0.17  0.5  -0.0  1.0
  C  C4  2  0.3  0.5  -0.0  1.0

Bi Bi C C C C
Bi Bi C C C C 0 3 - - o 0 4 o o - 0 5 o o - 1 2 o o + 1 3 o o + 1 4 + o o 1 5 o + o 2 3 o o o 2 4 + o - 2 5 o + - 3 4 + o - 3 5 o + - 4 5 o o o 