data_NbTlAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.65
_cell_length_b   4.65
_cell_length_c   4.65
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   NbTlAs
_chemical_formula_sum   'Nb1 Tl1 As1'
_cell_volume   70.96
_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
  Nb  Nb1  1  0.64  0.64  0.64  1.0
  Tl  Tl2  1  0.29  0.29  0.29  1.0
  As  As0  1  0.0  0.0  0.0  1.0

data_NbTlAs
_symmetry_space_group_name_H-M   R3m
_cell_length_a   4.65
_cell_length_b   4.65
_cell_length_c   11.38
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   NbTlAs
_chemical_formula_sum   'Nb3 Tl3 As3'
_cell_volume   212.89
_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
  Nb  Nb0  3  0.0  0.0  0.36  1.0
  Tl  Tl1  3  0.0  0.0  0.71  1.0
  As  As2  3  0.0  0.0  0.0  1.0

Nb Tl As
Nb Tl As 0 1 o o + 0 1 o + o 0 1 + o o 0 2 o + + 0 2 + o + 0 2 + + o 1 2 o o + 1 2 o + o 1 2 + o o 
NbTlAs crystallizes in the trigonal R3m space group. Nb(1) is bonded in a hexagonal planar geometry to three equivalent Tl(1) and three equivalent As(1) atoms. All Nb(1)-Tl(1) bond lengths are 2.70 Å. All Nb(1)-As(1) bond lengths are 2.70 Å. Tl(1) is bonded to three equivalent Nb(1) and four equivalent As(1) atoms to form distorted TlNb3As4 hexagonal pyramids that share corners with three equivalent As(1)Nb3Tl4 hexagonal pyramids, corners with six equivalent Tl(1)Nb3As4 hexagonal pyramids, edges with three equivalent As(1)Nb3Tl4 hexagonal pyramids, and edges with six equivalent Tl(1)Nb3As4 hexagonal pyramids. There are three shorter (2.74 Å) and one longer (3.26 Å) Tl(1)-As(1) bond length. As(1) is bonded to three equivalent Nb(1) and four equivalent Tl(1) atoms to form AsNb3Tl4 hexagonal pyramids that share corners with three equivalent Tl(1)Nb3As4 hexagonal pyramids, corners with six equivalent As(1)Nb3Tl4 hexagonal pyramids, edges with three equivalent Tl(1)Nb3As4 hexagonal pyramids, and edges with six equivalent As(1)Nb3Tl4 hexagonal pyramids.