data_RhC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.33
_cell_length_b   4.92
_cell_length_c   2.76
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   RhC2
_chemical_formula_sum   'Rh2 C4'
_cell_volume   58.79
_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
  Rh  Rh4  1  0.0  0.0  0.0  1.0
  Rh  Rh5  1  0.17  0.46  0.38  1.0
  C  C0  1  0.59  0.78  0.0  1.0
  C  C1  1  0.74  0.13  0.0  1.0
  C  C2  1  0.76  0.59  0.38  1.0
  C  C3  1  0.57  0.32  0.38  1.0

data_RhC2
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.76
_cell_length_b   4.33
_cell_length_c   4.92
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   RhC2
_chemical_formula_sum   'Rh2 C4'
_cell_volume   58.79
_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
  Rh  Rh0  1  0.0  0.0  0.0  1.0
  Rh  Rh1  1  0.38  0.17  0.46  1.0
  C  C2  1  -0.0  0.74  0.13  1.0
  C  C3  1  -0.0  0.59  0.78  1.0
  C  C4  1  0.38  0.57  0.32  1.0
  C  C5  1  0.38  0.76  0.59  1.0

Rh Rh C C C C
RhC2 crystallizes in the triclinic P1 space group. There are two inequivalent Rh sites. In the first Rh site, Rh(1) is bonded in a single-bond geometry to one C(2) and two equivalent C(1) atoms. The Rh(1)-C(2) bond length is 1.31 Å. There is one shorter (2.05 Å) and one longer (2.79 Å) Rh(1)-C(1) bond length. In the second Rh site, Rh(2) is bonded in a linear geometry to one C(1), one C(3), and one C(4) atom. The Rh(2)-C(1) bond length is 2.66 Å. The Rh(2)-C(3) bond length is 1.88 Å. The Rh(2)-C(4) bond length is 1.88 Å. There are four inequivalent C sites. In the first C site, C(1) is bonded in a 6-coordinate geometry to one Rh(2), two equivalent Rh(1), one C(2), and two equivalent C(3) atoms. The C(1)-C(2) bond length is 1.84 Å. There is one shorter (1.58 Å) and one longer (2.08 Å) C(1)-C(3) bond length. In the second C site, C(2) is bonded in a distorted single-bond geometry to one Rh(1), one C(1), and two equivalent C(4) atoms. There is one shorter (1.58 Å) and one longer (2.08 Å) C(2)-C(4) bond length. In the third C site, C(3) is bonded in a 3-coordinate geometry to one Rh(2), one C(4), and two equivalent C(1) atoms. The C(3)-C(4) bond length is 1.56 Å. In the fourth C site, C(4) is bonded in a 4-coordinate geometry to one Rh(2), one C(3), and two equivalent C(2) atoms.