The structure described by Ba3Nb2P4O18 crystallizes in the triclinic P-1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(2), one O(5), one O(6), two equivalent O(3), two equivalent O(9), and three equivalent O(8) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent O(4), two equivalent O(7), two equivalent O(9), and four equivalent O(2) atoms. Nb(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted NbO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-45°. In the second P site, P(2) is bonded to one O(1), one O(4), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-45°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Nb(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate 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 3-coordinate geometry to one Ba(1), one Nb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ba(2), one Nb(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to three 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(2), two equivalent Ba(1), and one P(2) atom. is represented by the CIF card [CIF]
data_Ba3Nb2(P2O9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.972
_cell_length_b   9.193
_cell_length_c   9.684
_cell_angle_alpha   88.417
_cell_angle_beta   101.197
_cell_angle_gamma   101.625
_symmetry_Int_Tables_number   1
_cell_volume   425.261
_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
  Ba  Ba0  1  0.048  0.283  0.911  1.0
  Ba  Ba1  1  0.500  0.500  0.500  1.0
  Ba  Ba2  1  0.952  0.717  0.089  1.0
  Nb  Nb3  1  0.744  0.892  0.729  1.0
  Nb  Nb4  1  0.256  0.108  0.271  1.0
  P  P5  1  0.808  0.366  0.217  1.0
  P  P6  1  0.691  0.865  0.359  1.0
  P  P7  1  0.309  0.135  0.641  1.0
  P  P8  1  0.192  0.634  0.783  1.0
  O  O9  1  0.558  0.005  0.363  1.0
  O  O10  1  0.011  0.506  0.687  1.0
  O  O11  1  0.738  0.938  0.905  1.0
  O  O12  1  0.242  0.192  0.490  1.0
  O  O13  1  0.962  0.233  0.211  1.0
  O  O14  1  0.970  0.922  0.303  1.0
  O  O15  1  0.456  0.695  0.715  1.0
  O  O16  1  0.278  0.586  0.935  1.0
  O  O17  1  0.262  0.062  0.095  1.0
  O  O18  1  0.442  0.995  0.637  1.0
  O  O19  1  0.490  0.257  0.741  1.0
  O  O20  1  0.758  0.808  0.510  1.0
  O  O21  1  0.038  0.767  0.789  1.0
  O  O22  1  0.030  0.078  0.697  1.0
  O  O23  1  0.722  0.414  0.065  1.0
  O  O24  1  0.989  0.494  0.313  1.0
  O  O25  1  0.510  0.743  0.259  1.0
  O  O26  1  0.544  0.305  0.285  1.0
[/CIF]
.
The structure described by Ba3Nb2P4O18 crystallizes in the triclinic P-1 space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(2), one O(5), one O(6), two equivalent O(3), two equivalent O(9), and three equivalent O(8) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent O(4), two equivalent O(7), two equivalent O(9), and four equivalent O(2) atoms. Nb(1) is bonded to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(7) atom to form distorted NbO6 octahedra that share corners with two equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(2), one O(5), one O(7), and one O(8) atom to form PO4 tetrahedra that share corners with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 23-45°. In the second P site, P(2) is bonded to one O(1), one O(4), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with three equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-45°. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Nb(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one P(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one Nb(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate 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 3-coordinate geometry to one Ba(1), one Nb(1), and one P(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Ba(2), one Nb(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to three 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(2), two equivalent Ba(1), and one P(2) atom. is represented by the CIF card [CIF]
data_Ba3Nb2(P2O9)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.972
_cell_length_b   9.193
_cell_length_c   9.684
_cell_angle_alpha   88.417
_cell_angle_beta   101.197
_cell_angle_gamma   101.625
_symmetry_Int_Tables_number   1
_cell_volume   425.261
_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
  Ba  Ba0  1  0.048  0.283  0.911  1.0
  Ba  Ba1  1  0.500  0.500  0.500  1.0
  Ba  Ba2  1  0.952  0.717  0.089  1.0
  Nb  Nb3  1  0.744  0.892  0.729  1.0
  Nb  Nb4  1  0.256  0.108  0.271  1.0
  P  P5  1  0.808  0.366  0.217  1.0
  P  P6  1  0.691  0.865  0.359  1.0
  P  P7  1  0.309  0.135  0.641  1.0
  P  P8  1  0.192  0.634  0.783  1.0
  O  O9  1  0.558  0.005  0.363  1.0
  O  O10  1  0.011  0.506  0.687  1.0
  O  O11  1  0.738  0.938  0.905  1.0
  O  O12  1  0.242  0.192  0.490  1.0
  O  O13  1  0.962  0.233  0.211  1.0
  O  O14  1  0.970  0.922  0.303  1.0
  O  O15  1  0.456  0.695  0.715  1.0
  O  O16  1  0.278  0.586  0.935  1.0
  O  O17  1  0.262  0.062  0.095  1.0
  O  O18  1  0.442  0.995  0.637  1.0
  O  O19  1  0.490  0.257  0.741  1.0
  O  O20  1  0.758  0.808  0.510  1.0
  O  O21  1  0.038  0.767  0.789  1.0
  O  O22  1  0.030  0.078  0.697  1.0
  O  O23  1  0.722  0.414  0.065  1.0
  O  O24  1  0.989  0.494  0.313  1.0
  O  O25  1  0.510  0.743  0.259  1.0
  O  O26  1  0.544  0.305  0.285  1.0
[/CIF]
.