data_AlTlAs2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.65
_cell_length_b   3.65
_cell_length_c   7.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   AlTlAs2
_chemical_formula_sum   'Al1 Tl1 As2'
_cell_volume   95.7
_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
  Al  Al0  1  0.0  0.0  0.75  1.0
  Tl  Tl3  1  0.83  0.83  0.78  1.0
  As  As1  1  0.83  0.83  0.12  1.0
  As  As2  1  0.0  0.0  0.1  1.0

data_AlTlAs2
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.17
_cell_length_b   5.17
_cell_length_c   7.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   AlTlAs2
_chemical_formula_sum   'Al2 Tl2 As4'
_cell_volume   191.39
_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
  Al  Al0  2  0.0  0.0  0.75  1.0
  Tl  Tl1  2  0.33  0.5  0.78  1.0
  As  As2  2  0.0  0.0  0.1  1.0
  As  As3  2  0.33  0.5  0.12  1.0

Al Tl As As
TlAlAs2 is Indium-like structured and crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two TlAlAs2 clusters. Tl(1) is bonded in a 1-coordinate geometry to one Al(1) and one As(1) atom. The Tl(1)-Al(1) bond length is 0.93 Å. The Tl(1)-As(1) bond length is 2.43 Å. Al(1) is bonded in a distorted single-bond geometry to one Tl(1) atom. There are two inequivalent As sites. In the first As site, As(1) is bonded in a distorted L-shaped geometry to one Tl(1) and one As(2) atom. The As(1)-As(2) bond length is 0.91 Å. In the second As site, As(2) is bonded in a 1-coordinate geometry to one As(1) atom.