data_MnTlAg
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.55
_cell_length_b   4.55
_cell_length_c   4.55
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MnTlAg
_chemical_formula_sum   'Mn1 Tl1 Ag1'
_cell_volume   66.73
_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
  Mn  Mn1  1  0.0  0.0  0.0  1.0
  Tl  Tl2  1  0.83  0.83  0.83  1.0
  Ag  Ag0  1  0.61  0.61  0.61  1.0

data_MnTlAg
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.55
_cell_length_b   4.55
_cell_length_c   11.15
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MnTlAg
_chemical_formula_sum   'Mn3 Tl3 Ag3'
_cell_volume   200.19
_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
  Mn  Mn0  3  0.0  0.0  0.0  1.0
  Tl  Tl1  3  0.0  0.0  0.17  1.0
  Ag  Ag2  3  0.0  0.0  0.39  1.0

Mn Tl Ag
Mn Tl Ag 0 1 - - - 0 2 o - - 0 2 - o - 0 2 - - o 1 2 o + o 1 2 + o o 1 2 o o + 1 2 o o o 
MnAgTl is half-Heusler structured and crystallizes in the trigonal R3m space group. Mn(1) is bonded in a 4-coordinate geometry to three equivalent Ag(1) and one Tl(1) atom. All Mn(1)-Ag(1) bond lengths are 2.70 Å. The Mn(1)-Tl(1) bond length is 1.91 Å. Ag(1) is bonded in a 7-coordinate geometry to three equivalent Mn(1) and four equivalent Tl(1) atoms. There is one shorter (2.45 Å) and three longer (2.92 Å) Ag(1)-Tl(1) bond lengths. Tl(1) is bonded in a 2-coordinate geometry to one Mn(1) and four equivalent Ag(1) atoms.