data_TlAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.65
_cell_length_b   6.65
_cell_length_c   5.15
_cell_angle_alpha   105.9
_cell_angle_beta   105.9
_cell_angle_gamma   31.97
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlAs
_chemical_formula_sum   'Tl2 As2'
_cell_volume   115.63
_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  Tl2  1  0.53  0.0  0.07  1.0
  Tl  Tl3  1  0.79  0.0  0.87  1.0
  As  As0  1  0.54  0.0  0.01  1.0
  As  As1  1  0.78  0.0  0.93  1.0

data_TlAs
_symmetry_space_group_name_H-M   P-1
_cell_length_a   3.66
_cell_length_b   5.15
_cell_length_c   6.65
_cell_angle_alpha   105.9
_cell_angle_beta   105.98
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   2
_chemical_formula_structural   TlAs
_chemical_formula_sum   'Tl2 As2'
_cell_volume   115.63
_cell_formula_units_Z   2
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
  Tl  Tl0  2  0.0  0.4  0.63  1.0
  As  As1  2  0.0  0.46  0.62  1.0

Tl Tl As As
Tl Tl As As 0 2 o o o 1 3 o o o 
TlAs is alpha carbon monoxide-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of two arsenic;thallium molecules. Tl(1) is bonded in a single-bond geometry to one As(1) atom. The Tl(1)-As(1) bond length is 0.34 Å. As(1) is bonded in a single-bond geometry to one Tl(1) atom.