data_TlSiSn
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.97
_cell_length_b   4.97
_cell_length_c   4.97
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlSiSn
_chemical_formula_sum   'Tl1 Si1 Sn1'
_cell_volume   86.63
_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  Tl2  1  0.76  0.76  0.76  1.0
  Si  Si0  1  0.0  0.0  0.0  1.0
  Sn  Sn1  1  0.51  0.51  0.51  1.0

data_TlSiSn
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.97
_cell_length_b   4.97
_cell_length_c   12.17
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   TlSiSn
_chemical_formula_sum   'Tl3 Si3 Sn3'
_cell_volume   259.9
_cell_formula_units_Z   3
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  0.24  1.0
  Si  Si1  3  0.0  0.0  0.0  1.0
  Sn  Sn2  3  0.0  0.0  0.49  1.0

Tl Si Sn
TlSnSi is half-Heusler structured and crystallizes in the trigonal R3m space group. Tl(1) is bonded in a body-centered cubic geometry to four equivalent Sn(1) and four equivalent Si(1) atoms. There is one shorter (2.97 Å) and three longer (3.07 Å) Tl(1)-Sn(1) bond lengths. There is one shorter (2.97 Å) and three longer (3.07 Å) Tl(1)-Si(1) bond lengths. Sn(1) is bonded to four equivalent Tl(1) atoms to form SnTl4 tetrahedra that share corners with four equivalent Si(1)Tl4 tetrahedra, corners with twelve equivalent Sn(1)Tl4 tetrahedra, and edges with six equivalent Si(1)Tl4 tetrahedra. Si(1) is bonded to four equivalent Tl(1) atoms to form SiTl4 tetrahedra that share corners with four equivalent Sn(1)Tl4 tetrahedra, corners with twelve equivalent Si(1)Tl4 tetrahedra, and edges with six equivalent Sn(1)Tl4 tetrahedra.