The crystal structure described by Ca3Ta4(O6F)2 crystallizes in the trigonal R-3m space group. Ca(1) is bonded to two equivalent O(1), four equivalent O(2), and two equivalent F(1) atoms to form distorted CaO6F2 hexagonal bipyramids that share edges with four equivalent Ca(1)O6F2 hexagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with four 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 TaO6 octahedra that share corners with six equivalent Ta(2)O6 octahedra and edges with six equivalent Ca(1)O6F2 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. 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 four equivalent Ca(1)O6F2 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 40-44°. There are two 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 4-coordinate geometry to two equivalent Ca(1), one Ta(1), and one Ta(2) atom. F(1) is bonded in a trigonal non-coplanar geometry to three equivalent Ca(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Ta4(O6F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.397
_cell_length_b   7.397
_cell_length_c   7.397
_cell_angle_alpha   60.841
_cell_angle_beta   60.841
_cell_angle_gamma   60.841
_symmetry_Int_Tables_number   1
_cell_volume   291.648
_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  0.000  0.500  0.500  1.0
  Ca  Ca1  1  0.500  0.500  0.000  1.0
  Ca  Ca2  1  0.500  0.000  0.500  1.0
  Ta  Ta3  1  0.000  0.000  0.000  1.0
  Ta  Ta4  1  0.500  0.000  0.000  1.0
  Ta  Ta5  1  0.000  0.000  0.500  1.0
  Ta  Ta6  1  0.000  0.500  0.000  1.0
  O  O7  1  0.944  0.315  0.315  1.0
  O  O8  1  0.318  0.929  0.929  1.0
  O  O9  1  0.315  0.315  0.944  1.0
  O  O10  1  0.929  0.929  0.318  1.0
  O  O11  1  0.929  0.318  0.929  1.0
  O  O12  1  0.315  0.944  0.315  1.0
  O  O13  1  0.056  0.685  0.685  1.0
  O  O14  1  0.682  0.071  0.071  1.0
  O  O15  1  0.685  0.685  0.056  1.0
  O  O16  1  0.071  0.071  0.682  1.0
  O  O17  1  0.071  0.682  0.071  1.0
  O  O18  1  0.685  0.056  0.685  1.0
  F  F19  1  0.363  0.363  0.363  1.0
  F  F20  1  0.637  0.637  0.637  1.0
[/CIF]
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The crystal structure described by Ca3Ta4(O6F)2 crystallizes in the trigonal R-3m space group. Ca(1) is bonded to two equivalent O(1), four equivalent O(2), and two equivalent F(1) atoms to form distorted CaO6F2 hexagonal bipyramids that share edges with four equivalent Ca(1)O6F2 hexagonal bipyramids, edges with two equivalent Ta(1)O6 octahedra, and edges with four 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 TaO6 octahedra that share corners with six equivalent Ta(2)O6 octahedra and edges with six equivalent Ca(1)O6F2 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. 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 four equivalent Ca(1)O6F2 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 40-44°. There are two 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 4-coordinate geometry to two equivalent Ca(1), one Ta(1), and one Ta(2) atom. F(1) is bonded in a trigonal non-coplanar geometry to three equivalent Ca(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ca3Ta4(O6F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.397
_cell_length_b   7.397
_cell_length_c   7.397
_cell_angle_alpha   60.841
_cell_angle_beta   60.841
_cell_angle_gamma   60.841
_symmetry_Int_Tables_number   1
_cell_volume   291.648
_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  0.000  0.500  0.500  1.0
  Ca  Ca1  1  0.500  0.500  0.000  1.0
  Ca  Ca2  1  0.500  0.000  0.500  1.0
  Ta  Ta3  1  0.000  0.000  0.000  1.0
  Ta  Ta4  1  0.500  0.000  0.000  1.0
  Ta  Ta5  1  0.000  0.000  0.500  1.0
  Ta  Ta6  1  0.000  0.500  0.000  1.0
  O  O7  1  0.944  0.315  0.315  1.0
  O  O8  1  0.318  0.929  0.929  1.0
  O  O9  1  0.315  0.315  0.944  1.0
  O  O10  1  0.929  0.929  0.318  1.0
  O  O11  1  0.929  0.318  0.929  1.0
  O  O12  1  0.315  0.944  0.315  1.0
  O  O13  1  0.056  0.685  0.685  1.0
  O  O14  1  0.682  0.071  0.071  1.0
  O  O15  1  0.685  0.685  0.056  1.0
  O  O16  1  0.071  0.071  0.682  1.0
  O  O17  1  0.071  0.682  0.071  1.0
  O  O18  1  0.685  0.056  0.685  1.0
  F  F19  1  0.363  0.363  0.363  1.0
  F  F20  1  0.637  0.637  0.637  1.0
[/CIF]
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