data_Cs2CaTa
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.52
_cell_length_b   6.52
_cell_length_c   6.52
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   Cs2CaTa
_chemical_formula_sum   'Cs2 Ca1 Ta1'
_cell_volume   196.01
_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
  Cs  Cs1  1  0.31  0.31  0.31  1.0
  Cs  Cs2  1  0.92  0.92  0.92  1.0
  Ca  Ca0  1  0.0  0.0  0.0  1.0
  Ta  Ta3  1  0.61  0.61  0.61  1.0

data_Cs2CaTa
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.52
_cell_length_b   6.52
_cell_length_c   15.97
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   Cs2CaTa
_chemical_formula_sum   'Cs6 Ca3 Ta3'
_cell_volume   588.02
_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
  Cs  Cs0  3  0.0  0.0  0.08  1.0
  Cs  Cs1  3  0.0  0.0  0.69  1.0
  Ca  Ca2  3  0.0  0.0  0.0  1.0
  Ta  Ta3  3  0.0  0.0  0.39  1.0

Cs Cs Ca Ta
Cs Cs Ca Ta 0 2 o o + 0 2 o + o 0 2 + o o 0 1 - - o 0 1 - o - 0 1 o - - 0 3 - o o 0 3 o - o 0 3 o o - 1 2 + + + 1 3 + o o 1 3 o + o 1 3 o o + 2 3 o - - 2 3 - o - 2 3 - - o 
Cs2CaTa crystallizes in the trigonal R3m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 3-coordinate geometry to four equivalent Ta(1) atoms. There are three shorter (3.79 Å) and one longer (4.88 Å) Cs(1)-Ta(1) bond length. In the second Cs site, Cs(2) is bonded in a single-bond geometry to one Ca(1) and four equivalent Ta(1) atoms. The Cs(2)-Ca(1) bond length is 1.35 Å. There are three shorter (3.79 Å) and one longer (4.88 Å) Cs(2)-Ta(1) bond length. Ca(1) is bonded in a single-bond geometry to one Cs(2) and three equivalent Ta(1) atoms. All Ca(1)-Ta(1) bond lengths are 3.87 Å. Ta(1) is bonded in a 11-coordinate geometry to four equivalent Cs(1), four equivalent Cs(2), and three equivalent Ca(1) atoms.