data_MnTl2As
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.15
_cell_length_b   5.15
_cell_length_c   5.15
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   MnTl2As
_chemical_formula_sum   'Mn1 Tl2 As1'
_cell_volume   96.85
_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  0.47  0.47  0.47  1.0
  Tl  Tl3  1  0.82  0.82  0.82  1.0
  As  As0  1  0.64  0.64  0.64  1.0

data_MnTl2As
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.15
_cell_length_b   5.15
_cell_length_c   12.63
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   MnTl2As
_chemical_formula_sum   'Mn3 Tl6 As3'
_cell_volume   290.54
_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  0.18  1.0
  Tl  Tl2  3  0.0  0.0  0.53  1.0
  As  As3  3  0.0  0.0  0.36  1.0

Mn Tl Tl As
Mn Tl Tl As 0 2 - - - 1 3 o o o 2 3 o o o 
MnTl2As crystallizes in the trigonal R3m space group. Mn(1) is bonded to one Tl(2) and three equivalent As(1) atoms to form distorted MnTlAs3 trigonal pyramids that share  a cornercorner with one As(1)Mn3Tl2 trigonal bipyramid and corners with six equivalent Mn(1)TlAs3 trigonal pyramids. The Mn(1)-Tl(2) bond length is 2.24 Å. All Mn(1)-As(1) bond lengths are 2.99 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded in a single-bond geometry to one As(1) atom. The Tl(1)-As(1) bond length is 2.24 Å. In the second Tl site, Tl(2) is bonded in a distorted linear geometry to one Mn(1) and one As(1) atom. The Tl(2)-As(1) bond length is 2.24 Å. As(1) is bonded to three equivalent Mn(1), one Tl(1), and one Tl(2) atom to form distorted AsMn3Tl2 trigonal bipyramids that share corners with six equivalent As(1)Mn3Tl2 trigonal bipyramids and  a cornercorner with one Mn(1)TlAs3 trigonal pyramid.