The structure described by Ba2NbP2O9F crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(3), one O(5), one O(7), one O(9), two equivalent O(1), two equivalent O(8), and one F(1) atom. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(4), one O(6), one O(8), one O(9), two equivalent O(2), two equivalent O(7), and one F(1) atom. Nb(1) is bonded to one O(3), one O(4), one O(5), one O(6), one O(9), and one F(1) atom to form NbO5F octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 38-42°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 33-46°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one P(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ba(1), one Nb(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ba(2), one Nb(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Nb(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ba(2), one Nb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Nb(1) atom. F(1) is bonded in a trigonal non-coplanar geometry to one Ba(1), one Ba(2), and one Nb(1) atom. is represented by the CIF file [CIF]
data_Ba2NbP2O9F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.283
_cell_length_b   7.195
_cell_length_c   9.163
_cell_angle_alpha   88.802
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   480.097
_cell_formula_units_Z   2
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
  Ba  Ba0  1  0.636  0.329  0.568  1.0
  Ba  Ba1  1  0.136  0.671  0.432  1.0
  Ba  Ba2  1  0.360  0.672  0.928  1.0
  Ba  Ba3  1  0.860  0.328  0.072  1.0
  Nb  Nb4  1  0.494  0.976  0.249  1.0
  Nb  Nb5  1  0.994  0.024  0.751  1.0
  P  P6  1  0.644  0.805  0.573  1.0
  P  P7  1  0.144  0.195  0.427  1.0
  P  P8  1  0.357  0.196  0.927  1.0
  P  P9  1  0.857  0.804  0.073  1.0
  O  O10  1  0.281  0.323  0.501  1.0
  O  O11  1  0.781  0.677  0.499  1.0
  O  O12  1  0.718  0.677  0.999  1.0
  O  O13  1  0.218  0.323  0.001  1.0
  O  O14  1  0.566  0.958  0.462  1.0
  O  O15  1  0.066  0.042  0.538  1.0
  O  O16  1  0.435  0.045  0.039  1.0
  O  O17  1  0.935  0.955  0.961  1.0
  O  O18  1  0.740  0.932  0.689  1.0
  O  O19  1  0.240  0.068  0.311  1.0
  O  O20  1  0.261  0.067  0.812  1.0
  O  O21  1  0.761  0.933  0.188  1.0
  O  O22  1  0.517  0.307  0.860  1.0
  O  O23  1  0.017  0.693  0.140  1.0
  O  O24  1  0.484  0.694  0.640  1.0
  O  O25  1  0.984  0.306  0.360  1.0
  O  O26  1  0.420  0.740  0.232  1.0
  O  O27  1  0.920  0.260  0.768  1.0
  F  F28  1  0.585  0.260  0.268  1.0
  F  F29  1  0.085  0.740  0.732  1.0
[/CIF]
.
The structure described by Ba2NbP2O9F crystallizes in the monoclinic P2_1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 9-coordinate geometry to one O(3), one O(5), one O(7), one O(9), two equivalent O(1), two equivalent O(8), and one F(1) atom. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(4), one O(6), one O(8), one O(9), two equivalent O(2), two equivalent O(7), and one F(1) atom. Nb(1) is bonded to one O(3), one O(4), one O(5), one O(6), one O(9), and one F(1) atom to form NbO5F octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(5), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 38-42°. In the second P site, P(2) is bonded to one O(2), one O(4), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O5F octahedra. The corner-sharing octahedral tilt angles range from 33-46°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one P(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ba(1), one Nb(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Ba(2), one Nb(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ba(1), one Nb(1), and one P(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Ba(2), one Nb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Ba(2), two equivalent Ba(1), and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one Nb(1) atom. F(1) is bonded in a trigonal non-coplanar geometry to one Ba(1), one Ba(2), and one Nb(1) atom. is represented by the CIF file [CIF]
data_Ba2NbP2O9F
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.283
_cell_length_b   7.195
_cell_length_c   9.163
_cell_angle_alpha   88.802
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   480.097
_cell_formula_units_Z   2
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
  Ba  Ba0  1  0.636  0.329  0.568  1.0
  Ba  Ba1  1  0.136  0.671  0.432  1.0
  Ba  Ba2  1  0.360  0.672  0.928  1.0
  Ba  Ba3  1  0.860  0.328  0.072  1.0
  Nb  Nb4  1  0.494  0.976  0.249  1.0
  Nb  Nb5  1  0.994  0.024  0.751  1.0
  P  P6  1  0.644  0.805  0.573  1.0
  P  P7  1  0.144  0.195  0.427  1.0
  P  P8  1  0.357  0.196  0.927  1.0
  P  P9  1  0.857  0.804  0.073  1.0
  O  O10  1  0.281  0.323  0.501  1.0
  O  O11  1  0.781  0.677  0.499  1.0
  O  O12  1  0.718  0.677  0.999  1.0
  O  O13  1  0.218  0.323  0.001  1.0
  O  O14  1  0.566  0.958  0.462  1.0
  O  O15  1  0.066  0.042  0.538  1.0
  O  O16  1  0.435  0.045  0.039  1.0
  O  O17  1  0.935  0.955  0.961  1.0
  O  O18  1  0.740  0.932  0.689  1.0
  O  O19  1  0.240  0.068  0.311  1.0
  O  O20  1  0.261  0.067  0.812  1.0
  O  O21  1  0.761  0.933  0.188  1.0
  O  O22  1  0.517  0.307  0.860  1.0
  O  O23  1  0.017  0.693  0.140  1.0
  O  O24  1  0.484  0.694  0.640  1.0
  O  O25  1  0.984  0.306  0.360  1.0
  O  O26  1  0.420  0.740  0.232  1.0
  O  O27  1  0.920  0.260  0.768  1.0
  F  F28  1  0.585  0.260  0.268  1.0
  F  F29  1  0.085  0.740  0.732  1.0
[/CIF]
.