data_[Mn18C21]
loop_
 _atom_type_symbol
 _atom_type_electronegativity
 _atom_type_radius
 _atom_type_ionic_radius
[
  Mn  1.5500  1.4000  0.6483
  C  2.5500  0.7000  0.3000
]
_symmetry_space_group_name_H-M [R-3m]
_cell_length_a [4.0716]
_cell_length_b [4.0716]
_cell_length_c [24.1852]
_cell_angle_alpha [90.0000]
_cell_angle_beta [90.0000]
_cell_angle_gamma [120.0000]
_symmetry_Int_Tables_number [166]
_chemical_formula_structural [Mn6C7]
_chemical_formula_sum '[Mn18 C21]'
_cell_volume [347.2194]
_cell_formula_units_Z [3]
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  Mn0  6  0.0000  0.0000  0.0729  1
  Mn  Mn1  6  0.0000  0.0000  0.1895  1
  Mn  Mn2  6  0.0000  0.0000  0.3495  1
  C  C3  18  0.0792  0.5396  0.9334  1
  C  C4  3  -0.0000  -0.0000  0.5000  1
]