data_CaTlAs4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.81
_cell_length_b   5.81
_cell_length_c   5.81
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CaTlAs4
_chemical_formula_sum   'Ca1 Tl1 As4'
_cell_volume   138.96
_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
  Ca  Ca4  1  0.0  0.0  0.0  1.0
  Tl  Tl5  1  0.06  0.06  0.06  1.0
  As  As0  1  0.1  0.1  0.13  1.0
  As  As1  1  0.1  0.13  0.1  1.0
  As  As2  1  0.13  0.1  0.1  1.0
  As  As3  1  0.13  0.13  0.13  1.0

data_CaTlAs4
_symmetry_space_group_name_H-M   R3m
_cell_length_a   5.81
_cell_length_b   5.81
_cell_length_c   14.24
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CaTlAs4
_chemical_formula_sum   'Ca3 Tl3 As12'
_cell_volume   416.87
_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
  Ca  Ca0  3  0.0  0.0  0.0  1.0
  Tl  Tl1  3  0.0  0.0  0.94  1.0
  As  As2  9  0.01  0.02  0.89  1.0
  As  As3  3  0.0  0.0  0.87  1.0

Ca Tl As As As As
CaTlAs4 is Copper structured and crystallizes in the trigonal R3m space group. The structure is zero-dimensional and consists of three CaTlAs4 clusters. Ca(1) is bonded in a single-bond geometry to one Tl(1) atom. The Ca(1)-Tl(1) bond length is 0.79 Å. Tl(1) is bonded in a distorted single-bond geometry to one Ca(1) and three equivalent As(1) atoms. All Tl(1)-As(1) bond lengths are 0.73 Å. There are two inequivalent As sites. In the first As site, As(2) is bonded in a 3-coordinate geometry to three equivalent As(1) atoms. All As(2)-As(1) bond lengths are 0.29 Å. In the second As site, As(1) is bonded in a 2-coordinate geometry to one Tl(1), one As(2), and two equivalent As(1) atoms. Both As(1)-As(1) bond lengths are 0.17 Å.