data_YTlSe
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.95
_cell_length_b   4.95
_cell_length_c   4.95
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   YTlSe
_chemical_formula_sum   'Y1 Tl1 Se1'
_cell_volume   85.92
_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
  Y  Y2  1  0.25  0.25  0.25  1.0
  Tl  Tl1  1  0.75  0.75  0.75  1.0
  Se  Se0  1  0.0  0.0  0.0  1.0

data_YTlSe
_symmetry_space_group_name_H-M   F-43m
_cell_length_a   7.0
_cell_length_b   7.0
_cell_length_c   7.0
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   90.0
_symmetry_Int_Tables_number   216
_chemical_formula_structural   YTlSe
_chemical_formula_sum   'Y4 Tl4 Se4'
_cell_volume   343.67
_cell_formula_units_Z   4
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  'y, -x, -z'
  3  '-x, -y, z'
  4  '-y, x, -z'
  5  'x, -y, -z'
  6  'y, x, z'
  7  '-x, y, -z'
  8  '-y, -x, z'
  9  'z, x, y'
  10  '-z, y, -x'
  11  'z, -x, -y'
  12  '-z, -y, x'
  13  '-z, x, -y'
  14  'z, y, x'
  15  '-z, -x, y'
  16  'z, -y, -x'
  17  'y, z, x'
  18  '-x, -z, y'
  19  '-y, z, -x'
  20  'x, -z, -y'
  21  '-y, -z, x'
  22  'x, z, y'
  23  'y, -z, -x'
  24  '-x, z, -y'
  25  'x+1/2, y+1/2, z'
  26  'y+1/2, -x+1/2, -z'
  27  '-x+1/2, -y+1/2, z'
  28  '-y+1/2, x+1/2, -z'
  29  'x+1/2, -y+1/2, -z'
  30  'y+1/2, x+1/2, z'
  31  '-x+1/2, y+1/2, -z'
  32  '-y+1/2, -x+1/2, z'
  33  'z+1/2, x+1/2, y'
  34  '-z+1/2, y+1/2, -x'
  35  'z+1/2, -x+1/2, -y'
  36  '-z+1/2, -y+1/2, x'
  37  '-z+1/2, x+1/2, -y'
  38  'z+1/2, y+1/2, x'
  39  '-z+1/2, -x+1/2, y'
  40  'z+1/2, -y+1/2, -x'
  41  'y+1/2, z+1/2, x'
  42  '-x+1/2, -z+1/2, y'
  43  '-y+1/2, z+1/2, -x'
  44  'x+1/2, -z+1/2, -y'
  45  '-y+1/2, -z+1/2, x'
  46  'x+1/2, z+1/2, y'
  47  'y+1/2, -z+1/2, -x'
  48  '-x+1/2, z+1/2, -y'
  49  'x+1/2, y, z+1/2'
  50  'y+1/2, -x, -z+1/2'
  51  '-x+1/2, -y, z+1/2'
  52  '-y+1/2, x, -z+1/2'
  53  'x+1/2, -y, -z+1/2'
  54  'y+1/2, x, z+1/2'
  55  '-x+1/2, y, -z+1/2'
  56  '-y+1/2, -x, z+1/2'
  57  'z+1/2, x, y+1/2'
  58  '-z+1/2, y, -x+1/2'
  59  'z+1/2, -x, -y+1/2'
  60  '-z+1/2, -y, x+1/2'
  61  '-z+1/2, x, -y+1/2'
  62  'z+1/2, y, x+1/2'
  63  '-z+1/2, -x, y+1/2'
  64  'z+1/2, -y, -x+1/2'
  65  'y+1/2, z, x+1/2'
  66  '-x+1/2, -z, y+1/2'
  67  '-y+1/2, z, -x+1/2'
  68  'x+1/2, -z, -y+1/2'
  69  '-y+1/2, -z, x+1/2'
  70  'x+1/2, z, y+1/2'
  71  'y+1/2, -z, -x+1/2'
  72  '-x+1/2, z, -y+1/2'
  73  'x, y+1/2, z+1/2'
  74  'y, -x+1/2, -z+1/2'
  75  '-x, -y+1/2, z+1/2'
  76  '-y, x+1/2, -z+1/2'
  77  'x, -y+1/2, -z+1/2'
  78  'y, x+1/2, z+1/2'
  79  '-x, y+1/2, -z+1/2'
  80  '-y, -x+1/2, z+1/2'
  81  'z, x+1/2, y+1/2'
  82  '-z, y+1/2, -x+1/2'
  83  'z, -x+1/2, -y+1/2'
  84  '-z, -y+1/2, x+1/2'
  85  '-z, x+1/2, -y+1/2'
  86  'z, y+1/2, x+1/2'
  87  '-z, -x+1/2, y+1/2'
  88  'z, -y+1/2, -x+1/2'
  89  'y, z+1/2, x+1/2'
  90  '-x, -z+1/2, y+1/2'
  91  '-y, z+1/2, -x+1/2'
  92  'x, -z+1/2, -y+1/2'
  93  '-y, -z+1/2, x+1/2'
  94  'x, z+1/2, y+1/2'
  95  'y, -z+1/2, -x+1/2'
  96  '-x, z+1/2, -y+1/2'
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
  Y  Y0  4  0.25  0.25  0.75  1.0
  Tl  Tl1  4  0.25  0.25  0.25  1.0
  Se  Se2  4  0.0  0.0  0.0  1.0

Y Tl Se
Y Tl Se 0 2 o o o 0 2 o o + 0 2 o + o 0 2 + o o 0 1 - - o 0 1 - o - 0 1 - o o 0 1 o - - 0 1 o - o 0 1 o o - 1 2 + o + 1 2 o + + 1 2 + + o 1 2 + + + 
YTlSe is half-Heusler structured and crystallizes in the trigonal R3m space group. Y(1) is bonded to four equivalent Se(1) atoms to form distorted YSe4 tetrahedra that share corners with four equivalent Tl(1)Se4 tetrahedra, corners with twelve equivalent Y(1)Se4 tetrahedra, and edges with six equivalent Tl(1)Se4 tetrahedra. There are three shorter (3.02 Å) and one longer (3.07 Å) Y(1)-Se(1) bond length. Tl(1) is bonded to four equivalent Se(1) atoms to form distorted TlSe4 tetrahedra that share corners with four equivalent Y(1)Se4 tetrahedra, corners with twelve equivalent Tl(1)Se4 tetrahedra, and edges with six equivalent Y(1)Se4 tetrahedra. There is one shorter (3.02 Å) and three longer (3.04 Å) Tl(1)-Se(1) bond lengths. Se(1) is bonded in a body-centered cubic geometry to four equivalent Y(1) and four equivalent Tl(1) atoms.