The material described by Ba6Na2Nb2P2O17 crystallizes in the trigonal P-3m1 space group. Na(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form NaO6 octahedra that share corners with three equivalent Nb(1)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(3)O6 cuboctahedra, and faces with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to three equivalent O(2), three equivalent O(3), and six equivalent O(1) atoms to form distorted BaO12 cuboctahedra that share corners with three equivalent Ba(3)O6 cuboctahedra, corners with nine equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ba(4)O12 cuboctahedra, faces with three equivalent Na(1)O6 octahedra, faces with four equivalent Nb(1)O6 octahedra, and  a faceface with one P(1)O4 tetrahedra. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(4), three equivalent O(1), and six equivalent O(2) atoms. In the third Ba site, Ba(3) is bonded to six equivalent O(2) atoms to form distorted BaO6 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with six equivalent P(1)O4 tetrahedra, and faces with two equivalent Na(1)O6 octahedra. In the fourth Ba site, Ba(4) is bonded to six equivalent O(1) and six equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(4)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Na(1)O6 octahedra, and faces with six equivalent Nb(1)O6 octahedra. Nb(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form NbO6 octahedra that share corners with three equivalent Na(1)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, faces with three equivalent Ba(4)O12 cuboctahedra, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. P(1) is bonded to one O(4) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Ba(3)O6 cuboctahedra, corners with three equivalent Na(1)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 17°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Ba(2), one Ba(4), two equivalent Ba(1), and one Nb(1) atom to form distorted OBa4NaNb octahedra that share corners with five equivalent O(3)Ba4Nb2 octahedra, corners with nine equivalent O(1)Ba4NaNb octahedra, edges with two equivalent O(3)Ba4Nb2 octahedra, faces with two equivalent O(3)Ba4Nb2 octahedra, and faces with four equivalent O(1)Ba4NaNb octahedra. The corner-sharing octahedral tilt angles range from 0-63°. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Na(1), one Ba(1), one Ba(3), two equivalent Ba(2), and one P(1) atom. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Ba(4), and two equivalent Nb(1) atoms to form distorted OBa4Nb2 octahedra that share corners with six equivalent O(3)Ba4Nb2 octahedra, corners with ten equivalent O(1)Ba4NaNb octahedra, edges with four equivalent O(1)Ba4NaNb octahedra, faces with four equivalent O(1)Ba4NaNb octahedra, and faces with four equivalent O(3)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(2) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba6Na2Nb2P2O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.850
_cell_length_b   5.850
_cell_length_c   14.632
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   433.707
_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  0.667  0.333  0.658  1.0
  Ba  Ba1  1  0.333  0.667  0.342  1.0
  Ba  Ba2  1  0.667  0.333  0.180  1.0
  Ba  Ba3  1  0.333  0.667  0.820  1.0
  Ba  Ba4  1  0.000  0.000  0.000  1.0
  Ba  Ba5  1  0.000  0.000  0.500  1.0
  Na  Na6  1  0.000  0.000  0.755  1.0
  Na  Na7  1  0.000  0.000  0.245  1.0
  Nb  Nb8  1  0.333  0.667  0.588  1.0
  Nb  Nb9  1  0.667  0.333  0.412  1.0
  P  P10  1  0.333  0.667  0.105  1.0
  P  P11  1  0.667  0.333  0.895  1.0
  O  O12  1  0.176  0.351  0.662  1.0
  O  O13  1  0.810  0.190  0.857  1.0
  O  O14  1  0.500  0.000  0.500  1.0
  O  O15  1  0.649  0.824  0.662  1.0
  O  O16  1  0.190  0.380  0.143  1.0
  O  O17  1  0.333  0.667  0.001  1.0
  O  O18  1  0.824  0.649  0.338  1.0
  O  O19  1  0.824  0.176  0.338  1.0
  O  O20  1  0.620  0.810  0.143  1.0
  O  O21  1  0.667  0.333  0.999  1.0
  O  O22  1  0.810  0.620  0.857  1.0
  O  O23  1  0.380  0.190  0.857  1.0
  O  O24  1  0.190  0.810  0.143  1.0
  O  O25  1  0.000  0.500  0.500  1.0
  O  O26  1  0.176  0.824  0.662  1.0
  O  O27  1  0.351  0.176  0.338  1.0
  O  O28  1  0.500  0.500  0.500  1.0
[/CIF]
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The material described by Ba6Na2Nb2P2O17 crystallizes in the trigonal P-3m1 space group. Na(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form NaO6 octahedra that share corners with three equivalent Nb(1)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra,  a faceface with one Ba(4)O12 cuboctahedra,  a faceface with one Ba(3)O6 cuboctahedra, and faces with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are four inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to three equivalent O(2), three equivalent O(3), and six equivalent O(1) atoms to form distorted BaO12 cuboctahedra that share corners with three equivalent Ba(3)O6 cuboctahedra, corners with nine equivalent Ba(1)O12 cuboctahedra, faces with three equivalent Ba(4)O12 cuboctahedra, faces with three equivalent Na(1)O6 octahedra, faces with four equivalent Nb(1)O6 octahedra, and  a faceface with one P(1)O4 tetrahedra. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to one O(4), three equivalent O(1), and six equivalent O(2) atoms. In the third Ba site, Ba(3) is bonded to six equivalent O(2) atoms to form distorted BaO6 cuboctahedra that share corners with six equivalent Ba(1)O12 cuboctahedra, corners with six equivalent P(1)O4 tetrahedra, and faces with two equivalent Na(1)O6 octahedra. In the fourth Ba site, Ba(4) is bonded to six equivalent O(1) and six equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with six equivalent Ba(4)O12 cuboctahedra, faces with six equivalent Ba(1)O12 cuboctahedra, faces with two equivalent Na(1)O6 octahedra, and faces with six equivalent Nb(1)O6 octahedra. Nb(1) is bonded to three equivalent O(1) and three equivalent O(3) atoms to form NbO6 octahedra that share corners with three equivalent Na(1)O6 octahedra, corners with three equivalent Nb(1)O6 octahedra, faces with three equivalent Ba(4)O12 cuboctahedra, and faces with four equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-3°. P(1) is bonded to one O(4) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Ba(3)O6 cuboctahedra, corners with three equivalent Na(1)O6 octahedra, and  a faceface with one Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 17°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Ba(2), one Ba(4), two equivalent Ba(1), and one Nb(1) atom to form distorted OBa4NaNb octahedra that share corners with five equivalent O(3)Ba4Nb2 octahedra, corners with nine equivalent O(1)Ba4NaNb octahedra, edges with two equivalent O(3)Ba4Nb2 octahedra, faces with two equivalent O(3)Ba4Nb2 octahedra, and faces with four equivalent O(1)Ba4NaNb octahedra. The corner-sharing octahedral tilt angles range from 0-63°. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Na(1), one Ba(1), one Ba(3), two equivalent Ba(2), and one P(1) atom. In the third O site, O(3) is bonded to two equivalent Ba(1), two equivalent Ba(4), and two equivalent Nb(1) atoms to form distorted OBa4Nb2 octahedra that share corners with six equivalent O(3)Ba4Nb2 octahedra, corners with ten equivalent O(1)Ba4NaNb octahedra, edges with four equivalent O(1)Ba4NaNb octahedra, faces with four equivalent O(1)Ba4NaNb octahedra, and faces with four equivalent O(3)Ba4Nb2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(2) and one P(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Ba6Na2Nb2P2O17
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.850
_cell_length_b   5.850
_cell_length_c   14.632
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   433.707
_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  0.667  0.333  0.658  1.0
  Ba  Ba1  1  0.333  0.667  0.342  1.0
  Ba  Ba2  1  0.667  0.333  0.180  1.0
  Ba  Ba3  1  0.333  0.667  0.820  1.0
  Ba  Ba4  1  0.000  0.000  0.000  1.0
  Ba  Ba5  1  0.000  0.000  0.500  1.0
  Na  Na6  1  0.000  0.000  0.755  1.0
  Na  Na7  1  0.000  0.000  0.245  1.0
  Nb  Nb8  1  0.333  0.667  0.588  1.0
  Nb  Nb9  1  0.667  0.333  0.412  1.0
  P  P10  1  0.333  0.667  0.105  1.0
  P  P11  1  0.667  0.333  0.895  1.0
  O  O12  1  0.176  0.351  0.662  1.0
  O  O13  1  0.810  0.190  0.857  1.0
  O  O14  1  0.500  0.000  0.500  1.0
  O  O15  1  0.649  0.824  0.662  1.0
  O  O16  1  0.190  0.380  0.143  1.0
  O  O17  1  0.333  0.667  0.001  1.0
  O  O18  1  0.824  0.649  0.338  1.0
  O  O19  1  0.824  0.176  0.338  1.0
  O  O20  1  0.620  0.810  0.143  1.0
  O  O21  1  0.667  0.333  0.999  1.0
  O  O22  1  0.810  0.620  0.857  1.0
  O  O23  1  0.380  0.190  0.857  1.0
  O  O24  1  0.190  0.810  0.143  1.0
  O  O25  1  0.000  0.500  0.500  1.0
  O  O26  1  0.176  0.824  0.662  1.0
  O  O27  1  0.351  0.176  0.338  1.0
  O  O28  1  0.500  0.500  0.500  1.0
[/CIF]
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