data_TlZnSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.98
_cell_length_b   4.98
_cell_length_c   4.98
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   TlZnSe
_chemical_formula_sum   'Tl1 Zn1 Se1'
_cell_volume   87.58
_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  Tl1  1  0.52  0.52  0.52  1.0
  Zn  Zn2  1  0.0  0.0  0.0  1.0
  Se  Se0  1  0.76  0.76  0.76  1.0

data_TlZnSe
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.98
_cell_length_b   4.98
_cell_length_c   12.21
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   TlZnSe
_chemical_formula_sum   'Tl3 Zn3 Se3'
_cell_volume   262.74
_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  0.48  1.0
  Zn  Zn1  3  0.0  0.0  0.0  1.0
  Se  Se2  3  0.0  0.0  0.24  1.0

Tl Zn Se
Tl Zn Se 0 1 o o + 0 1 o + o 0 1 o + + 0 1 + o o 0 1 + o + 0 1 + + o 0 2 o - o 0 2 - o o 0 2 o o - 0 2 o o o 1 2 - - - 1 2 - - o 1 2 o - - 1 2 - o - 
ZnTlSe is half-Heusler structured and crystallizes in the trigonal R3m space group. Zn(1) is bonded to four equivalent Se(1) atoms to form distorted ZnSe4 tetrahedra that share corners with four equivalent Tl(1)Se4 tetrahedra, corners with twelve equivalent Zn(1)Se4 tetrahedra, and edges with six equivalent Tl(1)Se4 tetrahedra. There is one shorter (2.90 Å) and three longer (3.11 Å) Zn(1)-Se(1) bond lengths. Tl(1) is bonded to four equivalent Se(1) atoms to form TlSe4 tetrahedra that share corners with four equivalent Zn(1)Se4 tetrahedra, corners with twelve equivalent Tl(1)Se4 tetrahedra, and edges with six equivalent Zn(1)Se4 tetrahedra. There is one shorter (2.90 Å) and three longer (3.11 Å) Tl(1)-Se(1) bond lengths. Se(1) is bonded in a body-centered cubic geometry to four equivalent Zn(1) and four equivalent Tl(1) atoms.