data_Cr2C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.61
_cell_length_b   2.78
_cell_length_c   7.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cr2C
_chemical_formula_sum   'Cr8 C4'
_cell_volume   109.71
_cell_formula_units_Z   4
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
  Cr  Cr4  1  0.75  0.7  0.24  1.0
  Cr  Cr5  1  0.05  0.09  0.75  1.0
  Cr  Cr6  1  0.55  0.7  0.28  1.0
  Cr  Cr7  1  0.85  0.09  0.79  1.0
  Cr  Cr8  1  0.74  0.7  0.71  1.0
  Cr  Cr9  1  0.67  0.09  0.2  1.0
  Cr  Cr10  1  0.93  0.7  0.83  1.0
  Cr  Cr11  1  0.87  0.09  0.32  1.0
  C  C0  1  0.69  0.7  0.84  1.0
  C  C1  1  0.11  0.09  0.32  1.0
  C  C2  1  0.49  0.7  0.71  1.0
  C  C3  1  0.91  0.09  0.19  1.0

data_Cr2C
_symmetry_space_group_name_H-M   P-1
_cell_length_a   2.78
_cell_length_b   5.61
_cell_length_c   7.03
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   Cr2C
_chemical_formula_sum   'Cr8 C4'
_cell_volume   109.71
_cell_formula_units_Z   4
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
  Cr  Cr0  2  0.2  0.25  0.24  1.0
  Cr  Cr1  2  0.2  0.87  0.68  1.0
  Cr  Cr2  2  0.2  0.05  0.28  1.0
  Cr  Cr3  2  0.2  0.07  0.8  1.0
  C  C4  2  0.2  0.31  0.81  1.0
  C  C5  2  0.2  0.11  0.68  1.0

Cr Cr Cr Cr Cr Cr Cr Cr C C C C
Cr Cr Cr Cr Cr Cr Cr Cr C C C C 0 5 o + o 0 2 o o o 0 7 o + o 1 3 - o o 1 6 - - o 2 5 o + o 3 4 o - o 3 6 o - o 4 8 o o o 4 6 o o o 4 10 o o o 5 11 o o o 5 7 o o o 6 8 o o o 7 11 o o o 7 9 + o o 8 10 o o o 9 11 - o o 
Cr2C crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two Cr2C clusters. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 3-coordinate geometry to one Cr(2), one Cr(4), and one C(1) atom. The Cr(1)-Cr(2) bond length is 1.14 Å. The Cr(1)-Cr(4) bond length is 1.21 Å. The Cr(1)-C(1) bond length is 1.46 Å. In the second Cr site, Cr(2) is bonded in a distorted single-bond geometry to one Cr(1) atom. In the third Cr site, Cr(3) is bonded in a single-bond geometry to one C(1) and one C(2) atom. The Cr(3)-C(1) bond length is 0.90 Å. The Cr(3)-C(2) bond length is 1.36 Å. In the fourth Cr site, Cr(4) is bonded in a 1-coordinate geometry to one Cr(1) and one C(1) atom. The Cr(4)-C(1) bond length is 1.36 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a single-bond geometry to one Cr(1), one Cr(3), and one Cr(4) atom. In the second C site, C(2) is bonded in a distorted single-bond geometry to one Cr(3) atom.