data_TlFeSi2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.93
_cell_length_b   5.93
_cell_length_c   5.93
_cell_angle_alpha   153.19
_cell_angle_beta   133.9
_cell_angle_gamma   54.14
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlFeSi2
_chemical_formula_sum   'Tl1 Fe1 Si2'
_cell_volume   67.58
_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  0.0  0.0  0.28  1.0
  Fe  Fe0  1  0.0  0.0  0.0  1.0
  Si  Si1  1  0.38  0.0  0.99  1.0
  Si  Si2  1  0.0  0.32  0.29  1.0

data_TlFeSi2
_symmetry_space_group_name_H-M   P1
_cell_length_a   2.75
_cell_length_b   4.65
_cell_length_c   5.93
_cell_angle_alpha   113.05
_cell_angle_beta   103.41
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlFeSi2
_chemical_formula_sum   'Tl1 Fe1 Si2'
_cell_volume   67.58
_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  Tl0  1  0.0  0.28  0.28  1.0
  Fe  Fe1  1  0.0  0.0  0.0  1.0
  Si  Si2  1  0.0  0.99  0.61  1.0
  Si  Si3  1  0.68  0.97  0.97  1.0

Tl Fe Si Si
FeTlSi2 crystallizes in the triclinic P1 space group. Fe(1) is bonded in a 1-coordinate geometry to one Tl(1), one Si(1), and one Si(2) atom. The Fe(1)-Tl(1) bond length is 1.69 Å. The Fe(1)-Si(1) bond length is 2.27 Å. The Fe(1)-Si(2) bond length is 0.87 Å. Tl(1) is bonded in a 6-coordinate geometry to one Fe(1), two equivalent Tl(1), one Si(2), and two equivalent Si(1) atoms. Both Tl(1)-Tl(1) bond lengths are 2.75 Å. The Tl(1)-Si(2) bond length is 1.87 Å. There is one shorter (2.79 Å) and one longer (3.09 Å) Tl(1)-Si(1) bond length. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded in a 3-coordinate geometry to one Fe(1) and two equivalent Tl(1) atoms. In the second Si site, Si(2) is bonded in a distorted single-bond geometry to one Fe(1) and one Tl(1) atom.