data_KTlCu
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.11
_cell_length_b   5.11
_cell_length_c   5.11
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KTlCu
_chemical_formula_sum   'K1 Tl1 Cu1'
_cell_volume   94.58
_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
  K  K1  1  0.0  0.0  0.0  1.0
  Tl  Tl2  1  0.62  0.62  0.62  1.0
  Cu  Cu0  1  0.81  0.81  0.81  1.0

data_KTlCu
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.11
_cell_length_b   5.11
_cell_length_c   12.53
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   KTlCu
_chemical_formula_sum   'K3 Tl3 Cu3'
_cell_volume   283.73
_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
  K  K0  3  0.0  0.0  0.0  1.0
  Tl  Tl1  3  0.0  0.0  0.38  1.0
  Cu  Cu2  3  0.0  0.0  0.19  1.0

K Tl Cu
KCuTl is half-Heusler structured and crystallizes in the trigonal R3m space group. K(1) is bonded in a distorted single-bond geometry to four equivalent Cu(1) and three equivalent Tl(1) atoms. There is one shorter (2.40 Å) and three longer (3.44 Å) K(1)-Cu(1) bond lengths. All K(1)-Tl(1) bond lengths are 3.02 Å. Cu(1) is bonded in a 2-coordinate geometry to four equivalent K(1) and one Tl(1) atom. The Cu(1)-Tl(1) bond length is 2.40 Å. Tl(1) is bonded in a 4-coordinate geometry to three equivalent K(1) and one Cu(1) atom.