The material described by Ca3Nb4(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 Nb(1)O6 octahedra, and edges with four equivalent Nb(2)O6 octahedra. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to six equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Nb(2)O6 octahedra and edges with six equivalent Ca(1)O6F2 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. In the second Nb site, Nb(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(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 Nb(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Nb(1), and one Nb(2) atom. F(1) is bonded in a trigonal planar geometry to three equivalent Ca(1) atoms. is represented by the CIF card [CIF]
data_Ca3Nb4(O6F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.439
_cell_length_b   7.439
_cell_length_c   7.439
_cell_angle_alpha   60.886
_cell_angle_beta   60.886
_cell_angle_gamma   60.886
_symmetry_Int_Tables_number   1
_cell_volume   296.933
_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
  Nb  Nb3  1  0.000  0.000  0.000  1.0
  Nb  Nb4  1  0.500  0.000  0.000  1.0
  Nb  Nb5  1  0.000  0.000  0.500  1.0
  Nb  Nb6  1  0.000  0.500  0.000  1.0
  O  O7  1  0.944  0.315  0.315  1.0
  O  O8  1  0.319  0.928  0.928  1.0
  O  O9  1  0.315  0.315  0.944  1.0
  O  O10  1  0.928  0.928  0.319  1.0
  O  O11  1  0.928  0.319  0.928  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  0.681  0.072  0.072  1.0
  O  O15  1  0.685  0.685  0.056  1.0
  O  O16  1  0.072  0.072  0.681  1.0
  O  O17  1  0.072  0.681  0.072  1.0
  O  O18  1  0.685  0.056  0.685  1.0
  F  F19  1  0.359  0.359  0.359  1.0
  F  F20  1  0.641  0.641  0.641  1.0
[/CIF]
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The material described by Ca3Nb4(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 Nb(1)O6 octahedra, and edges with four equivalent Nb(2)O6 octahedra. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to six equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Nb(2)O6 octahedra and edges with six equivalent Ca(1)O6F2 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. In the second Nb site, Nb(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(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 Nb(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Nb(1), and one Nb(2) atom. F(1) is bonded in a trigonal planar geometry to three equivalent Ca(1) atoms. is represented by the CIF card [CIF]
data_Ca3Nb4(O6F)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.439
_cell_length_b   7.439
_cell_length_c   7.439
_cell_angle_alpha   60.886
_cell_angle_beta   60.886
_cell_angle_gamma   60.886
_symmetry_Int_Tables_number   1
_cell_volume   296.933
_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
  Nb  Nb3  1  0.000  0.000  0.000  1.0
  Nb  Nb4  1  0.500  0.000  0.000  1.0
  Nb  Nb5  1  0.000  0.000  0.500  1.0
  Nb  Nb6  1  0.000  0.500  0.000  1.0
  O  O7  1  0.944  0.315  0.315  1.0
  O  O8  1  0.319  0.928  0.928  1.0
  O  O9  1  0.315  0.315  0.944  1.0
  O  O10  1  0.928  0.928  0.319  1.0
  O  O11  1  0.928  0.319  0.928  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  0.681  0.072  0.072  1.0
  O  O15  1  0.685  0.685  0.056  1.0
  O  O16  1  0.072  0.072  0.681  1.0
  O  O17  1  0.072  0.681  0.072  1.0
  O  O18  1  0.685  0.056  0.685  1.0
  F  F19  1  0.359  0.359  0.359  1.0
  F  F20  1  0.641  0.641  0.641  1.0
[/CIF]
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