data_TlGa2Se
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.7
_cell_length_b   3.7
_cell_length_c   7.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlGa2Se
_chemical_formula_sum   'Tl1 Ga2 Se1'
_cell_volume   96.03
_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
  Tl  Tl3  1  0.85  0.85  0.28  1.0
  Ga  Ga0  1  0.0  0.0  0.35  1.0
  Ga  Ga1  1  0.85  0.85  0.83  1.0
  Se  Se2  1  0.0  0.0  0.03  1.0

data_TlGa2Se
_symmetry_space_group_name_H-M   Cm
_cell_length_a   5.24
_cell_length_b   5.24
_cell_length_c   7.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   8
_chemical_formula_structural   TlGa2Se
_chemical_formula_sum   'Tl2 Ga4 Se2'
_cell_volume   192.05
_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
  Tl  Tl0  2  0.35  0.5  0.28  1.0
  Ga  Ga1  2  0.0  0.0  0.35  1.0
  Ga  Ga2  2  0.35  0.5  0.83  1.0
  Se  Se3  2  0.0  0.0  0.03  1.0

Tl Ga Ga Se
Tl Ga Ga Se 0 1 + + o 0 3 + + o 2 3 + + + 
TlGa2Se crystallizes in the monoclinic Cm space group. The structure is zero-dimensional and consists of two TlGa2Se clusters. Tl(1) is bonded in a distorted water-like geometry to one Ga(1) and one Se(1) atom. The Tl(1)-Ga(1) bond length is 0.92 Å. The Tl(1)-Se(1) bond length is 1.89 Å. There are two inequivalent Ga sites. In the first Ga site, Ga(1) is bonded in a single-bond geometry to one Tl(1) atom. In the second Ga site, Ga(2) is bonded in a single-bond geometry to one Se(1) atom. The Ga(2)-Se(1) bond length is 1.63 Å. Se(1) is bonded in a distorted bent 120 degrees geometry to one Tl(1) and one Ga(2) atom.