The compound described by CaTa4O14 crystallizes in the trigonal R-3m space group. Ca(1) is bonded to two equivalent O(3) and six equivalent O(1) atoms to form CaO8 hexagonal bipyramids that share edges with six equivalent Ta(2)O6 octahedra. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to six equivalent O(2) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 37°. In the second Ta site, Ta(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Ta(2)O6 octahedra, and edges with two equivalent Ca(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 37-42°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1) and two equivalent Ta(2) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(2) atom. In the third O site, O(3) is bonded in a single-bond geometry to one Ca(1) atom. is represented by the CIF file [CIF]
data_CaTa4O14
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.527
_cell_length_b   7.527
_cell_length_c   7.527
_cell_angle_alpha   59.258
_cell_angle_beta   59.258
_cell_angle_gamma   59.258
_symmetry_Int_Tables_number   1
_cell_volume   296.423
_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  Ca0  1  0.500  0.500  0.500  1.0
  Ta  Ta1  1  0.000  0.000  0.000  1.0
  Ta  Ta2  1  0.500  0.000  0.000  1.0
  Ta  Ta3  1  0.000  0.000  0.500  1.0
  Ta  Ta4  1  0.000  0.500  0.000  1.0
  O  O5  1  0.923  0.317  0.317  1.0
  O  O6  1  0.311  0.940  0.940  1.0
  O  O7  1  0.317  0.317  0.923  1.0
  O  O8  1  0.940  0.940  0.311  1.0
  O  O9  1  0.940  0.311  0.940  1.0
  O  O10  1  0.317  0.923  0.317  1.0
  O  O11  1  0.077  0.683  0.683  1.0
  O  O12  1  0.689  0.060  0.060  1.0
  O  O13  1  0.683  0.683  0.077  1.0
  O  O14  1  0.060  0.060  0.689  1.0
  O  O15  1  0.060  0.689  0.060  1.0
  O  O16  1  0.683  0.077  0.683  1.0
  O  O17  1  0.365  0.365  0.365  1.0
  O  O18  1  0.635  0.635  0.635  1.0
[/CIF]
.
The compound described by CaTa4O14 crystallizes in the trigonal R-3m space group. Ca(1) is bonded to two equivalent O(3) and six equivalent O(1) atoms to form CaO8 hexagonal bipyramids that share edges with six equivalent Ta(2)O6 octahedra. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to six equivalent O(2) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 37°. In the second Ta site, Ta(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TaO6 octahedra that share corners with two equivalent Ta(1)O6 octahedra, corners with four equivalent Ta(2)O6 octahedra, and edges with two equivalent Ca(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 37-42°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1) and two equivalent Ta(2) atoms. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Ta(1) and one Ta(2) atom. In the third O site, O(3) is bonded in a single-bond geometry to one Ca(1) atom. is represented by the CIF file [CIF]
data_CaTa4O14
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.527
_cell_length_b   7.527
_cell_length_c   7.527
_cell_angle_alpha   59.258
_cell_angle_beta   59.258
_cell_angle_gamma   59.258
_symmetry_Int_Tables_number   1
_cell_volume   296.423
_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  Ca0  1  0.500  0.500  0.500  1.0
  Ta  Ta1  1  0.000  0.000  0.000  1.0
  Ta  Ta2  1  0.500  0.000  0.000  1.0
  Ta  Ta3  1  0.000  0.000  0.500  1.0
  Ta  Ta4  1  0.000  0.500  0.000  1.0
  O  O5  1  0.923  0.317  0.317  1.0
  O  O6  1  0.311  0.940  0.940  1.0
  O  O7  1  0.317  0.317  0.923  1.0
  O  O8  1  0.940  0.940  0.311  1.0
  O  O9  1  0.940  0.311  0.940  1.0
  O  O10  1  0.317  0.923  0.317  1.0
  O  O11  1  0.077  0.683  0.683  1.0
  O  O12  1  0.689  0.060  0.060  1.0
  O  O13  1  0.683  0.683  0.077  1.0
  O  O14  1  0.060  0.060  0.689  1.0
  O  O15  1  0.060  0.689  0.060  1.0
  O  O16  1  0.683  0.077  0.683  1.0
  O  O17  1  0.365  0.365  0.365  1.0
  O  O18  1  0.635  0.635  0.635  1.0
[/CIF]
.