data_TlC2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.9
_cell_length_b   4.9
_cell_length_c   4.9
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlC2
_chemical_formula_sum   'Tl2 C4'
_cell_volume   83.31
_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
  Tl  Tl4  1  0.0  0.0  0.0  1.0
  Tl  Tl5  1  0.73  0.73  0.73  1.0
  C  C0  1  0.6  0.6  0.33  1.0
  C  C1  1  0.33  0.6  0.6  1.0
  C  C2  1  0.6  0.33  0.6  1.0
  C  C3  1  0.33  0.33  0.33  1.0

data_TlC2
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.9
_cell_length_b   4.9
_cell_length_c   12.01
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   TlC2
_chemical_formula_sum   'Tl6 C12'
_cell_volume   249.94
_cell_formula_units_Z   6
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  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+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
  Tl  Tl0  3  0.0  0.0  0.0  1.0
  Tl  Tl1  3  0.0  0.0  0.27  1.0
  C  C2  9  0.18  0.09  0.49  1.0
  C  C3  3  0.0  0.0  0.67  1.0

Tl Tl C C C C
Tl Tl C C C C 0 2 - - o 0 2 - o o 0 2 o - o 0 1 - - - 0 1 - - o 0 1 - o - 0 1 o - - 0 4 - o - 0 4 - o o 0 4 o o - 0 5 - o o 0 5 o - o 0 5 o o - 0 3 o - - 0 3 o - o 0 3 o o - 1 4 o o o 1 4 o + o 1 3 o o o 1 3 + o o 1 2 o o o 1 2 o o + 1 5 o o + 1 5 o + o 1 5 + o o 2 4 o o o 2 3 o o o 2 5 o o o 3 4 o o o 3 5 o o o 4 5 o o o 
TlC2 crystallizes in the trigonal R3m space group. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a 6-coordinate geometry to three equivalent C(1) and three equivalent C(2) atoms. All Tl(1)-C(1) bond lengths are 2.79 Å. All Tl(1)-C(2) bond lengths are 2.83 Å. In the second Tl site, Tl(2) is bonded in a 3-coordinate geometry to six equivalent C(1) atoms. There are three shorter (2.47 Å) and three longer (2.77 Å) Tl(2)-C(1) bond lengths. There are two inequivalent C sites. In the first C site, C(1) is bonded in a 5-coordinate geometry to one Tl(1), two equivalent Tl(2), and two equivalent C(1) atoms. Both C(1)-C(1) bond lengths are 1.31 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to three equivalent Tl(1) atoms.