data_Tc2C
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.2
_cell_length_b   5.2
_cell_length_c   5.2
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tc2C
_chemical_formula_sum   'Tc8 C4'
_cell_volume   140.22
_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
  Tc  Tc4  1  0.81  0.41  0.39  1.0
  Tc  Tc5  1  0.39  0.79  0.81  1.0
  Tc  Tc6  1  0.41  0.39  0.81  1.0
  Tc  Tc7  1  0.79  0.81  0.39  1.0
  Tc  Tc8  1  0.39  0.81  0.41  1.0
  Tc  Tc9  1  0.81  0.39  0.79  1.0
  Tc  Tc10  1  0.79  0.79  0.79  1.0
  Tc  Tc11  1  0.41  0.41  0.41  1.0
  C  C0  1  0.6  0.0  0.6  1.0
  C  C1  1  0.0  0.6  0.6  1.0
  C  C2  1  0.0  0.0  0.0  1.0
  C  C3  1  0.6  0.6  0.0  1.0

data_Tc2C
_symmetry_space_group_name_H-M   R3
_cell_length_a   7.35
_cell_length_b   7.35
_cell_length_c   9.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   146
_chemical_formula_structural   Tc2C
_chemical_formula_sum   'Tc24 C12'
_cell_volume   420.65
_cell_formula_units_Z   12
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  'x+1/3, y+2/3, z+2/3'
  5  '-y+1/3, x-y+2/3, z+2/3'
  6  '-x+y+1/3, -x+2/3, z+2/3'
  7  'x+2/3, y+1/3, z+1/3'
  8  '-y+2/3, x-y+1/3, z+1/3'
  9  '-x+y+2/3, -x+1/3, z+1/3'
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
  Tc  Tc0  9  0.06  0.52  0.33  1.0
  Tc  Tc1  9  0.19  0.79  0.2  1.0
  Tc  Tc2  3  0.0  0.0  0.41  1.0
  Tc  Tc3  3  0.0  0.0  0.79  1.0
  C  C4  9  0.2  0.4  0.4  1.0
  C  C5  3  0.0  0.0  0.0  1.0

Tc Tc Tc Tc Tc Tc Tc Tc C C C C
Tc2C crystallizes in the trigonal R3 space group. There are four inequivalent Tc sites. In the first Tc site, Tc(1) is bonded in a distorted single-bond geometry to one Tc(4) and three equivalent C(1) atoms. The Tc(1)-Tc(4) bond length is 2.09 Å. There are a spread of Tc(1)-C(1) bond distances ranging from 1.78-2.61 Å. In the second Tc site, Tc(2) is bonded in a 2-coordinate geometry to one C(2) and three equivalent C(1) atoms. The Tc(2)-C(2) bond length is 2.50 Å. There are a spread of Tc(2)-C(1) bond distances ranging from 1.78-2.50 Å. In the third Tc site, Tc(3) is bonded in a tetrahedral geometry to one C(2) and three equivalent C(1) atoms. The Tc(3)-C(2) bond length is 1.89 Å. All Tc(3)-C(1) bond lengths are 1.78 Å. In the fourth Tc site, Tc(4) is bonded in a 6-coordinate geometry to three equivalent Tc(1) and three equivalent C(1) atoms. All Tc(4)-C(1) bond lengths are 2.54 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 8-coordinate geometry to one Tc(3), one Tc(4), three equivalent Tc(1), and three equivalent Tc(2) atoms. In the second C site, C(2) is bonded in a trigonal pyramidal geometry to one Tc(3) and three equivalent Tc(2) atoms.