The compound described by Ta9PO25 crystallizes in the tetragonal I-4 space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Ta site, Ta(2) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 2-31°. In the third Ta site, Ta(3) is bonded to one O(3), one O(4), one O(5), one O(7), and two equivalent O(6) atoms to form distorted TaO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-31°. P(1) is bonded to four equivalent O(7) atoms to form PO4 tetrahedra that share corners with four equivalent Ta(3)O6 octahedra. The corner-sharing octahedral tilt angles are 39°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a linear geometry to one Ta(1) and one Ta(2) atom. In the third O site, O(3) is bonded in a linear geometry to one Ta(2) and one Ta(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ta(3) and two equivalent Ta(2) atoms. In the fifth O site, O(5) is bonded in a linear geometry to one Ta(2) and one Ta(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ta(2) and two equivalent Ta(3) atoms. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ta(3) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta9PO25
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.215
_cell_length_b   11.215
_cell_length_c   11.215
_cell_angle_alpha   91.678
_cell_angle_beta   91.678
_cell_angle_gamma   160.297
_symmetry_Int_Tables_number   1
_cell_volume   468.575
_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  1.000  1.0
  Ta  Ta1  1  0.115  0.788  0.887  1.0
  Ta  Ta2  1  0.883  0.670  0.557  1.0
  Ta  Ta3  1  0.674  0.117  0.787  1.0
  Ta  Ta4  1  0.212  0.098  0.327  1.0
  Ta  Ta5  1  0.772  0.885  0.673  1.0
  Ta  Ta6  1  0.330  0.887  0.213  1.0
  Ta  Ta7  1  0.113  0.326  0.443  1.0
  Ta  Ta8  1  0.902  0.228  0.113  1.0
  P  P9  1  0.750  0.250  0.500  1.0
  O  O10  1  0.500  0.500  0.000  1.0
  O  O11  1  0.057  0.888  0.939  1.0
  O  O12  1  0.808  0.763  0.604  1.0
  O  O13  1  0.623  0.256  0.860  1.0
  O  O14  1  0.998  0.729  0.712  1.0
  O  O15  1  0.796  0.192  0.955  1.0
  O  O16  1  0.345  0.145  0.511  1.0
  O  O17  1  0.166  0.655  0.800  1.0
  O  O18  1  0.744  0.604  0.367  1.0
  O  O19  1  0.585  0.096  0.616  1.0
  O  O20  1  0.904  0.520  0.489  1.0
  O  O21  1  0.112  0.051  0.169  1.0
  O  O22  1  0.713  0.002  0.730  1.0
  O  O23  1  0.271  0.983  0.270  1.0
  O  O24  1  0.882  0.943  0.831  1.0
  O  O25  1  0.031  0.415  0.511  1.0
  O  O26  1  0.480  0.969  0.384  1.0
  O  O27  1  0.237  0.377  0.633  1.0
  O  O28  1  0.855  0.366  0.200  1.0
  O  O29  1  0.634  0.834  0.489  1.0
  O  O30  1  0.237  0.841  0.045  1.0
  O  O31  1  0.017  0.287  0.288  1.0
  O  O32  1  0.396  0.763  0.140  1.0
  O  O33  1  0.159  0.204  0.396  1.0
  O  O34  1  0.949  0.118  0.061  1.0
[/CIF]
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The compound described by Ta9PO25 crystallizes in the tetragonal I-4 space group. There are three inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form corner-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Ta site, Ta(2) is bonded to one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles range from 2-31°. In the third Ta site, Ta(3) is bonded to one O(3), one O(4), one O(5), one O(7), and two equivalent O(6) atoms to form distorted TaO6 octahedra that share corners with two equivalent Ta(2)O6 octahedra, corners with two equivalent Ta(3)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 2-31°. P(1) is bonded to four equivalent O(7) atoms to form PO4 tetrahedra that share corners with four equivalent Ta(3)O6 octahedra. The corner-sharing octahedral tilt angles are 39°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a linear geometry to two equivalent Ta(1) atoms. In the second O site, O(2) is bonded in a linear geometry to one Ta(1) and one Ta(2) atom. In the third O site, O(3) is bonded in a linear geometry to one Ta(2) and one Ta(3) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ta(3) and two equivalent Ta(2) atoms. In the fifth O site, O(5) is bonded in a linear geometry to one Ta(2) and one Ta(3) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one Ta(2) and two equivalent Ta(3) atoms. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Ta(3) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ta9PO25
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.215
_cell_length_b   11.215
_cell_length_c   11.215
_cell_angle_alpha   91.678
_cell_angle_beta   91.678
_cell_angle_gamma   160.297
_symmetry_Int_Tables_number   1
_cell_volume   468.575
_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  1.000  1.0
  Ta  Ta1  1  0.115  0.788  0.887  1.0
  Ta  Ta2  1  0.883  0.670  0.557  1.0
  Ta  Ta3  1  0.674  0.117  0.787  1.0
  Ta  Ta4  1  0.212  0.098  0.327  1.0
  Ta  Ta5  1  0.772  0.885  0.673  1.0
  Ta  Ta6  1  0.330  0.887  0.213  1.0
  Ta  Ta7  1  0.113  0.326  0.443  1.0
  Ta  Ta8  1  0.902  0.228  0.113  1.0
  P  P9  1  0.750  0.250  0.500  1.0
  O  O10  1  0.500  0.500  0.000  1.0
  O  O11  1  0.057  0.888  0.939  1.0
  O  O12  1  0.808  0.763  0.604  1.0
  O  O13  1  0.623  0.256  0.860  1.0
  O  O14  1  0.998  0.729  0.712  1.0
  O  O15  1  0.796  0.192  0.955  1.0
  O  O16  1  0.345  0.145  0.511  1.0
  O  O17  1  0.166  0.655  0.800  1.0
  O  O18  1  0.744  0.604  0.367  1.0
  O  O19  1  0.585  0.096  0.616  1.0
  O  O20  1  0.904  0.520  0.489  1.0
  O  O21  1  0.112  0.051  0.169  1.0
  O  O22  1  0.713  0.002  0.730  1.0
  O  O23  1  0.271  0.983  0.270  1.0
  O  O24  1  0.882  0.943  0.831  1.0
  O  O25  1  0.031  0.415  0.511  1.0
  O  O26  1  0.480  0.969  0.384  1.0
  O  O27  1  0.237  0.377  0.633  1.0
  O  O28  1  0.855  0.366  0.200  1.0
  O  O29  1  0.634  0.834  0.489  1.0
  O  O30  1  0.237  0.841  0.045  1.0
  O  O31  1  0.017  0.287  0.288  1.0
  O  O32  1  0.396  0.763  0.140  1.0
  O  O33  1  0.159  0.204  0.396  1.0
  O  O34  1  0.949  0.118  0.061  1.0
[/CIF]
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