data_Tl2CrAs
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.16
_cell_length_b   5.16
_cell_length_c   5.16
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Tl2CrAs
_chemical_formula_sum   'Tl2 Cr1 As1'
_cell_volume   97.21
_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
  Tl  Tl2  1  0.82  0.82  0.82  1.0
  Tl  Tl3  1  0.65  0.65  0.65  1.0
  Cr  Cr1  1  0.0  0.0  0.0  1.0
  As  As0  1  0.47  0.47  0.47  1.0

data_Tl2CrAs
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.16
_cell_length_b   5.16
_cell_length_c   12.64
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Tl2CrAs
_chemical_formula_sum   'Tl6 Cr3 As3'
_cell_volume   291.62
_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
  Tl  Tl0  3  0.0  0.0  0.18  1.0
  Tl  Tl1  3  0.0  0.0  0.35  1.0
  Cr  Cr2  3  0.0  0.0  0.0  1.0
  As  As3  3  0.0  0.0  0.53  1.0

Tl Tl Cr As
Tl Tl Cr As 0 1 o o o 0 2 + + + 1 3 o o o 
CrTl2As crystallizes in the trigonal R3m space group. Cr(1) is bonded to one Tl(1) and three equivalent Tl(2) atoms to form distorted CrTl4 trigonal pyramids that share corners with three equivalent Tl(1)TlCrAs3 trigonal bipyramids, corners with six equivalent Cr(1)Tl4 trigonal pyramids, and edges with three equivalent As(1)Tl4 trigonal pyramids. The Cr(1)-Tl(1) bond length is 2.22 Å. All Cr(1)-Tl(2) bond lengths are 2.99 Å. There are two inequivalent Tl sites. In the first Tl site, Tl(1) is bonded to one Cr(1), one Tl(2), and three equivalent As(1) atoms to form TlTlCrAs3 trigonal bipyramids that share corners with six equivalent Tl(1)TlCrAs3 trigonal bipyramids,  a cornercorner with one As(1)Tl4 trigonal pyramid, and corners with three equivalent Cr(1)Tl4 trigonal pyramids. The Tl(1)-Tl(2) bond length is 2.22 Å. All Tl(1)-As(1) bond lengths are 2.99 Å. In the second Tl site, Tl(2) is bonded in a 1-coordinate geometry to three equivalent Cr(1), one Tl(1), and one As(1) atom. The Tl(2)-As(1) bond length is 2.22 Å. As(1) is bonded to one Tl(2) and three equivalent Tl(1) atoms to form distorted AsTl4 trigonal pyramids that share  a cornercorner with one Tl(1)TlCrAs3 trigonal bipyramid, corners with six equivalent As(1)Tl4 trigonal pyramids, and edges with three equivalent Cr(1)Tl4 trigonal pyramids.