The crystal structure described by Ta3O7F crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to four equivalent O(1) and two equivalent F(1) atoms to form TaO4F2 octahedra that share corners with two equivalent Ta(1)O4F2 octahedra, corners with four equivalent Ta(2)O7 pentagonal bipyramids, and edges with two equivalent Ta(2)O7 pentagonal bipyramids. The corner-sharing octahedra are not tilted. In the second Ta site, Ta(2) is bonded to one O(2), two equivalent O(3), and four equivalent O(1) atoms to form TaO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O4F2 octahedra, corners with three equivalent Ta(2)O7 pentagonal bipyramids,  an edgeedge with one Ta(1)O4F2 octahedra, and edges with two equivalent Ta(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ta(1) and two equivalent Ta(2) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent Ta(2) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ta(2) atoms. F(1) is bonded in a linear geometry to two equivalent Ta(1) atoms. is represented by the CIF file [CIF]
data_Ta3O7F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.942
_cell_length_b   6.209
_cell_length_c   6.209
_cell_angle_alpha   114.754
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   138.003
_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
  Ta  Ta0  1  0.000  0.000  0.000  1.0
  Ta  Ta1  1  0.000  0.316  0.684  1.0
  Ta  Ta2  1  0.000  0.684  0.316  1.0
  O  O3  1  0.000  0.331  0.048  1.0
  O  O4  1  0.000  0.500  0.500  1.0
  O  O5  1  0.500  0.301  0.699  1.0
  O  O6  1  0.500  0.699  0.301  1.0
  O  O7  1  0.000  0.048  0.331  1.0
  O  O8  1  0.000  0.669  0.952  1.0
  O  O9  1  0.000  0.952  0.669  1.0
  F  F10  1  0.500  0.000  0.000  1.0
[/CIF]
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The crystal structure described by Ta3O7F crystallizes in the orthorhombic Cmmm space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to four equivalent O(1) and two equivalent F(1) atoms to form TaO4F2 octahedra that share corners with two equivalent Ta(1)O4F2 octahedra, corners with four equivalent Ta(2)O7 pentagonal bipyramids, and edges with two equivalent Ta(2)O7 pentagonal bipyramids. The corner-sharing octahedra are not tilted. In the second Ta site, Ta(2) is bonded to one O(2), two equivalent O(3), and four equivalent O(1) atoms to form TaO7 pentagonal bipyramids that share corners with two equivalent Ta(1)O4F2 octahedra, corners with three equivalent Ta(2)O7 pentagonal bipyramids,  an edgeedge with one Ta(1)O4F2 octahedra, and edges with two equivalent Ta(2)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 37°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ta(1) and two equivalent Ta(2) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent Ta(2) atoms. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ta(2) atoms. F(1) is bonded in a linear geometry to two equivalent Ta(1) atoms. is represented by the CIF file [CIF]
data_Ta3O7F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   3.942
_cell_length_b   6.209
_cell_length_c   6.209
_cell_angle_alpha   114.754
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   138.003
_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
  Ta  Ta0  1  0.000  0.000  0.000  1.0
  Ta  Ta1  1  0.000  0.316  0.684  1.0
  Ta  Ta2  1  0.000  0.684  0.316  1.0
  O  O3  1  0.000  0.331  0.048  1.0
  O  O4  1  0.000  0.500  0.500  1.0
  O  O5  1  0.500  0.301  0.699  1.0
  O  O6  1  0.500  0.699  0.301  1.0
  O  O7  1  0.000  0.048  0.331  1.0
  O  O8  1  0.000  0.669  0.952  1.0
  O  O9  1  0.000  0.952  0.669  1.0
  F  F10  1  0.500  0.000  0.000  1.0
[/CIF]
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