data_Mn3C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.56
_cell_length_b   6.56
_cell_length_c   6.56
_cell_angle_alpha   23.72
_cell_angle_beta   23.72
_cell_angle_gamma   23.72
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Mn3C
_chemical_formula_sum   'Mn3 C1'
_cell_volume   40.17
_cell_formula_units_Z   1
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
  Mn  Mn1  1  0.0  0.0  0.91  1.0
  Mn  Mn2  1  0.0  0.0  0.56  1.0
  Mn  Mn3  1  0.0  0.0  0.22  1.0
  C  C0  1  0.0  0.0  0.0  1.0

data_Mn3C
_symmetry_space_group_name_H-M   Cm
_cell_length_a   4.67
_cell_length_b   2.7
_cell_length_c   6.56
_cell_angle_alpha   90.0
_cell_angle_beta   103.73
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   Mn3C
_chemical_formula_sum   'Mn6 C2'
_cell_volume   80.34
_cell_formula_units_Z   2
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
  Mn  Mn0  2  0.0  0.0  0.09  1.0
  Mn  Mn1  2  0.0  0.0  0.44  1.0
  Mn  Mn2  2  0.0  0.0  0.78  1.0
  C  C3  2  0.0  0.0  0.0  1.0

Mn Mn Mn C
Mn Mn Mn C 0 3 o o + 0 1 o o o 1 1 o + - 1 1 + - o 1 1 + o - 1 2 o o o 1 3 o o + 2 3 o o o 
Mn3C crystallizes in the monoclinic Cm space group. There are four inequivalent Mn sites. In the first Mn site, Mn(1) is bonded in a single-bond geometry to one Mn(2) and one C(1) atom. The Mn(1)-Mn(2) bond length is 2.26 Å. The Mn(1)-C(1) bond length is 0.60 Å. In the second Mn site, Mn(2) is bonded in a 8-coordinate geometry to one Mn(1); one Mn(3); and six Mn(2,2) atoms. The Mn(2)-Mn(3) bond length is 2.26 Å. All Mn(2)-Mn(2,2) bond lengths are 2.70 Å. In the third Mn site, Mn(3) is bonded in a single-bond geometry to one Mn(2) and one C(1) atom. The Mn(3)-C(1) bond length is 1.43 Å. In the fourth Mn site, Mn(2) is bonded in a 8-coordinate geometry to one Mn(1); one Mn(3); and six Mn(2,2) atoms. The Mn(2)-Mn(1) bond length is 2.26 Å. The Mn(2)-Mn(3) bond length is 2.26 Å. Both Mn(2)-Mn(2) bond lengths are 2.70 Å. C(1) is bonded in a distorted linear geometry to one Mn(1) and one Mn(3) atom.