The structure described by BaNb7O9 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded to four equivalent O(4) and eight equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with eight equivalent Nb(3)O5 square pyramids. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. In the second Nb site, Nb(2) is bonded in a square co-planar geometry to one O(1), one O(3), and two equivalent O(2) atoms. In the third Nb site, Nb(3) is bonded to one O(4) and four equivalent O(3) atoms to form NbO5 square pyramids that share corners with five equivalent Nb(3)O5 square pyramids and faces with four equivalent Ba(1)O12 cuboctahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a square co-planar geometry to two equivalent Nb(1) and two equivalent Nb(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to four equivalent Nb(2) atoms. In the third O site, O(3) is bonded to two equivalent Ba(1), one Nb(2), and two equivalent Nb(3) atoms to form a mixture of distorted edge and corner-sharing OBa2Nb3 trigonal bipyramids. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1) and two equivalent Nb(3) atoms. is represented by the CIF card [CIF]
data_BaNb7O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.234
_cell_length_b   4.234
_cell_length_c   12.529
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   224.582
_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  0.000  0.000  0.000  1.0
  Nb  Nb1  1  0.500  0.500  0.500  1.0
  Nb  Nb2  1  0.500  0.000  0.329  1.0
  Nb  Nb3  1  0.000  0.500  0.329  1.0
  Nb  Nb4  1  0.500  0.000  0.671  1.0
  Nb  Nb5  1  0.000  0.500  0.671  1.0
  Nb  Nb6  1  0.500  0.500  0.169  1.0
  Nb  Nb7  1  0.500  0.500  0.831  1.0
  O  O8  1  0.000  0.500  0.500  1.0
  O  O9  1  0.500  0.000  0.500  1.0
  O  O10  1  0.000  0.000  0.335  1.0
  O  O11  1  0.000  0.000  0.665  1.0
  O  O12  1  0.000  0.500  0.160  1.0
  O  O13  1  0.500  0.000  0.160  1.0
  O  O14  1  0.000  0.500  0.840  1.0
  O  O15  1  0.500  0.000  0.840  1.0
  O  O16  1  0.500  0.500  0.000  1.0
[/CIF]
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The structure described by BaNb7O9 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded to four equivalent O(4) and eight equivalent O(3) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(1)O12 cuboctahedra, faces with four equivalent Ba(1)O12 cuboctahedra, and faces with eight equivalent Nb(3)O5 square pyramids. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a square co-planar geometry to four equivalent O(1) atoms. In the second Nb site, Nb(2) is bonded in a square co-planar geometry to one O(1), one O(3), and two equivalent O(2) atoms. In the third Nb site, Nb(3) is bonded to one O(4) and four equivalent O(3) atoms to form NbO5 square pyramids that share corners with five equivalent Nb(3)O5 square pyramids and faces with four equivalent Ba(1)O12 cuboctahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a square co-planar geometry to two equivalent Nb(1) and two equivalent Nb(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to four equivalent Nb(2) atoms. In the third O site, O(3) is bonded to two equivalent Ba(1), one Nb(2), and two equivalent Nb(3) atoms to form a mixture of distorted edge and corner-sharing OBa2Nb3 trigonal bipyramids. In the fourth O site, O(4) is bonded in a distorted linear geometry to four equivalent Ba(1) and two equivalent Nb(3) atoms. is represented by the CIF card [CIF]
data_BaNb7O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   4.234
_cell_length_b   4.234
_cell_length_c   12.529
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   224.582
_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  0.000  0.000  0.000  1.0
  Nb  Nb1  1  0.500  0.500  0.500  1.0
  Nb  Nb2  1  0.500  0.000  0.329  1.0
  Nb  Nb3  1  0.000  0.500  0.329  1.0
  Nb  Nb4  1  0.500  0.000  0.671  1.0
  Nb  Nb5  1  0.000  0.500  0.671  1.0
  Nb  Nb6  1  0.500  0.500  0.169  1.0
  Nb  Nb7  1  0.500  0.500  0.831  1.0
  O  O8  1  0.000  0.500  0.500  1.0
  O  O9  1  0.500  0.000  0.500  1.0
  O  O10  1  0.000  0.000  0.335  1.0
  O  O11  1  0.000  0.000  0.665  1.0
  O  O12  1  0.000  0.500  0.160  1.0
  O  O13  1  0.500  0.000  0.160  1.0
  O  O14  1  0.000  0.500  0.840  1.0
  O  O15  1  0.500  0.000  0.840  1.0
  O  O16  1  0.500  0.500  0.000  1.0
[/CIF]
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