The compound described by Cs3TaO8 crystallizes in the tetragonal I-42m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form CsO8 hexagonal bipyramids that share corners with four equivalent Ta(1)O8 hexagonal bipyramids, corners with four equivalent O(1)Cs3TaO trigonal bipyramids, and edges with two equivalent Ta(1)O8 hexagonal bipyramids. In the second Cs site, Cs(2) is bonded in a 12-coordinate geometry to four equivalent O(1) and eight equivalent O(2) atoms. Ta(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted TaO8 hexagonal bipyramids that share corners with four equivalent Cs(1)O8 hexagonal bipyramids, corners with four equivalent O(1)Cs3TaO trigonal bipyramids, and edges with two equivalent Cs(1)O8 hexagonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Cs(1), two equivalent Cs(2), one Ta(1), and one O(2) atom to form distorted OCs3TaO trigonal bipyramids that share  a cornercorner with one Cs(1)O8 hexagonal bipyramid,  a cornercorner with one Ta(1)O8 hexagonal bipyramid, corners with ten equivalent O(1)Cs3TaO trigonal bipyramids, and  an edgeedge with one O(1)Cs3TaO trigonal bipyramid. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Cs(1), four equivalent Cs(2), one Ta(1), and one O(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cs3TaO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.695
_cell_length_b   6.695
_cell_length_c   6.695
_cell_angle_alpha   103.489
_cell_angle_beta   112.543
_cell_angle_gamma   112.543
_symmetry_Int_Tables_number   1
_cell_volume   229.124
_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  0.000  0.500  0.500  1.0
  Cs  Cs1  1  0.500  0.250  0.750  1.0
  Cs  Cs2  1  0.500  0.750  0.250  1.0
  Ta  Ta3  1  0.000  0.000  0.000  1.0
  O  O4  1  0.741  0.049  0.049  1.0
  O  O5  1  0.000  0.787  0.179  1.0
  O  O6  1  0.000  0.692  0.951  1.0
  O  O7  1  0.259  0.308  0.308  1.0
  O  O8  1  0.000  0.951  0.692  1.0
  O  O9  1  0.000  0.179  0.787  1.0
  O  O10  1  0.392  0.213  0.213  1.0
  O  O11  1  0.608  0.821  0.821  1.0
[/CIF]
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The compound described by Cs3TaO8 crystallizes in the tetragonal I-42m space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form CsO8 hexagonal bipyramids that share corners with four equivalent Ta(1)O8 hexagonal bipyramids, corners with four equivalent O(1)Cs3TaO trigonal bipyramids, and edges with two equivalent Ta(1)O8 hexagonal bipyramids. In the second Cs site, Cs(2) is bonded in a 12-coordinate geometry to four equivalent O(1) and eight equivalent O(2) atoms. Ta(1) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted TaO8 hexagonal bipyramids that share corners with four equivalent Cs(1)O8 hexagonal bipyramids, corners with four equivalent O(1)Cs3TaO trigonal bipyramids, and edges with two equivalent Cs(1)O8 hexagonal bipyramids. There are two inequivalent O sites. In the first O site, O(1) is bonded to one Cs(1), two equivalent Cs(2), one Ta(1), and one O(2) atom to form distorted OCs3TaO trigonal bipyramids that share  a cornercorner with one Cs(1)O8 hexagonal bipyramid,  a cornercorner with one Ta(1)O8 hexagonal bipyramid, corners with ten equivalent O(1)Cs3TaO trigonal bipyramids, and  an edgeedge with one O(1)Cs3TaO trigonal bipyramid. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Cs(1), four equivalent Cs(2), one Ta(1), and one O(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Cs3TaO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.695
_cell_length_b   6.695
_cell_length_c   6.695
_cell_angle_alpha   103.489
_cell_angle_beta   112.543
_cell_angle_gamma   112.543
_symmetry_Int_Tables_number   1
_cell_volume   229.124
_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  0.000  0.500  0.500  1.0
  Cs  Cs1  1  0.500  0.250  0.750  1.0
  Cs  Cs2  1  0.500  0.750  0.250  1.0
  Ta  Ta3  1  0.000  0.000  0.000  1.0
  O  O4  1  0.741  0.049  0.049  1.0
  O  O5  1  0.000  0.787  0.179  1.0
  O  O6  1  0.000  0.692  0.951  1.0
  O  O7  1  0.259  0.308  0.308  1.0
  O  O8  1  0.000  0.951  0.692  1.0
  O  O9  1  0.000  0.179  0.787  1.0
  O  O10  1  0.392  0.213  0.213  1.0
  O  O11  1  0.608  0.821  0.821  1.0
[/CIF]
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