data_CsSr2Ta
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.14
_cell_length_b   6.14
_cell_length_c   6.14
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   CsSr2Ta
_chemical_formula_sum   'Cs1 Sr2 Ta1'
_cell_volume   163.84
_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  Cs0  1  0.0  0.0  0.0  1.0
  Sr  Sr1  1  0.51  0.51  0.51  1.0
  Sr  Sr2  1  0.17  0.17  0.17  1.0
  Ta  Ta3  1  0.34  0.34  0.34  1.0

data_CsSr2Ta
_symmetry_space_group_name_H-M   R3m
_cell_length_a   6.14
_cell_length_b   6.14
_cell_length_c   15.04
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   CsSr2Ta
_chemical_formula_sum   'Cs3 Sr6 Ta3'
_cell_volume   491.53
_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  0.0  1.0
  Sr  Sr1  3  0.0  0.0  0.49  1.0
  Sr  Sr2  3  0.0  0.0  0.83  1.0
  Ta  Ta3  3  0.0  0.0  0.66  1.0

Cs Sr Sr Ta
CsSr2Ta crystallizes in the trigonal R3m space group. Cs(1) is bonded to one Sr(2) and three equivalent Ta(1) atoms to form distorted CsSrTa3 trigonal pyramids that share  a cornercorner with one Ta(1)Cs3Sr2 trigonal bipyramid and corners with six equivalent Cs(1)SrTa3 trigonal pyramids. The Cs(1)-Sr(2) bond length is 2.58 Å. All Cs(1)-Ta(1) bond lengths are 3.55 Å. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded in a single-bond geometry to one Ta(1) atom. The Sr(1)-Ta(1) bond length is 2.58 Å. In the second Sr site, Sr(2) is bonded in a distorted linear geometry to one Cs(1) and one Ta(1) atom. The Sr(2)-Ta(1) bond length is 2.58 Å. Ta(1) is bonded to three equivalent Cs(1), one Sr(1), and one Sr(2) atom to form distorted TaCs3Sr2 trigonal bipyramids that share corners with six equivalent Ta(1)Cs3Sr2 trigonal bipyramids and  a cornercorner with one Cs(1)SrTa3 trigonal pyramid.