data_Bi2C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.53
_cell_length_b   6.53
_cell_length_c   8.82
_cell_angle_alpha   129.21
_cell_angle_beta   129.21
_cell_angle_gamma   30.76
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Bi2C
_chemical_formula_sum   'Bi4 C2'
_cell_volume   145.42
_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  0.69  0.0  0.94  1.0
  Bi  Bi1  1  0.62  0.0  0.69  1.0
  Bi  Bi2  1  0.2  0.0  0.97  1.0
  Bi  Bi3  1  0.13  0.0  0.72  1.0
  C  C4  1  0.51  0.0  0.6  1.0
  C  C5  1  0.3  0.0  0.07  1.0

data_Bi2C
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.47
_cell_length_b   6.53
_cell_length_c   6.9
_cell_angle_alpha   82.03
_cell_angle_beta   75.46
_cell_angle_gamma   74.62
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Bi2C
_chemical_formula_sum   'Bi4 C2'
_cell_volume   145.42
_cell_formula_units_Z   2
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-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  2  0.0  0.15  0.64  1.0
  Bi  Bi1  2  0.0  0.33  0.39  1.0
  C  C2  2  0.0  0.16  0.73  1.0

Bi Bi Bi Bi C C
CBi2 crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two CBi2 clusters. C(1) is bonded in a single-bond geometry to one Bi(2) atom. The C(1)-Bi(2) bond length is 0.66 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded in a distorted single-bond geometry to one Bi(2) atom. The Bi(1)-Bi(2) bond length is 1.97 Å. In the second Bi site, Bi(2) is bonded in a single-bond geometry to one C(1) and one Bi(1) atom.