The material described by Na2Ti9O19 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a 7-coordinate geometry to one O(9), three equivalent O(5), and three equivalent O(7) atoms. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(2), one O(4), and two equivalent O(8) atoms. In the second Ti site, Ti(2) is bonded to one O(1), one O(10), one O(3), one O(5), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 29-41°. In the third Ti site, Ti(3) is bonded to one O(10), one O(2), one O(3), one O(8), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 28°. In the fourth Ti site, Ti(4) is bonded to one O(3), one O(6), one O(7), one O(8), and two equivalent O(1) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 31-39°. In the fifth Ti site, Ti(5) is bonded to two equivalent O(5), two equivalent O(7), and two equivalent O(9) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 0-41°. There are ten inequivalent O sites. In the first O site, O(7) is bonded in a 5-coordinate geometry to three equivalent Na(1), one Ti(4), and one Ti(5) atom. In the second O site, O(8) is bonded to one Ti(3), one Ti(4), and two equivalent Ti(1) atoms to form a mixture of distorted corner and edge-sharing OTi4 trigonal pyramids. In the third O site, O(9) is bonded in a square co-planar geometry to two equivalent Na(1) and two equivalent Ti(5) atoms. In the fourth O site, O(10) is bonded in a 3-coordinate geometry to one Ti(1), one Ti(2), and one Ti(3) atom. In the fifth O site, O(1) is bonded to one Ti(1), one Ti(2), and two equivalent Ti(4) atoms to form a mixture of distorted corner and edge-sharing OTi4 trigonal pyramids. In the sixth O site, O(2) is bonded in a linear geometry to one Ti(1) and one Ti(3) atom. In the seventh O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Ti(2), one Ti(3), and one Ti(4) atom. In the eighth O site, O(4) is bonded in a distorted T-shaped geometry to one Ti(1) and two equivalent Ti(3) atoms. In the ninth O site, O(5) is bonded in a 5-coordinate geometry to three equivalent Na(1), one Ti(2), and one Ti(5) atom. In the tenth O site, O(6) is bonded in a 3-coordinate geometry to one Ti(4) and two equivalent Ti(2) atoms. is represented by the CIF file [CIF]
data_Na2Ti9O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.434
_cell_length_b   6.434
_cell_length_c   15.798
_cell_angle_alpha   75.938
_cell_angle_beta   75.938
_cell_angle_gamma   34.435
_symmetry_Int_Tables_number   1
_cell_volume   357.672
_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
  Na  Na0  1  0.323  0.323  0.492  1.0
  Na  Na1  1  0.677  0.677  0.508  1.0
  Ti  Ti2  1  0.187  0.187  0.882  1.0
  Ti  Ti3  1  0.813  0.813  0.118  1.0
  Ti  Ti4  1  0.915  0.915  0.295  1.0
  Ti  Ti5  1  0.108  0.108  0.118  1.0
  Ti  Ti6  1  0.788  0.788  0.707  1.0
  Ti  Ti7  1  0.000  0.000  0.500  1.0
  Ti  Ti8  1  0.212  0.212  0.293  1.0
  Ti  Ti9  1  0.085  0.085  0.705  1.0
  Ti  Ti10  1  0.892  0.892  0.882  1.0
  O  O11  1  0.249  0.249  0.731  1.0
  O  O12  1  0.126  0.126  0.998  1.0
  O  O13  1  0.073  0.073  0.258  1.0
  O  O14  1  0.352  0.352  0.883  1.0
  O  O15  1  0.927  0.927  0.742  1.0
  O  O16  1  0.874  0.874  0.002  1.0
  O  O17  1  0.648  0.648  0.117  1.0
  O  O18  1  0.900  0.900  0.415  1.0
  O  O19  1  0.376  0.376  0.294  1.0
  O  O20  1  0.751  0.751  0.269  1.0
  O  O21  1  0.152  0.152  0.410  1.0
  O  O22  1  0.272  0.272  0.142  1.0
  O  O23  1  0.728  0.728  0.858  1.0
  O  O24  1  0.624  0.624  0.706  1.0
  O  O25  1  0.500  0.500  0.500  1.0
  O  O26  1  0.951  0.951  0.153  1.0
  O  O27  1  0.049  0.049  0.847  1.0
  O  O28  1  0.100  0.100  0.585  1.0
  O  O29  1  0.848  0.848  0.590  1.0
[/CIF]
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The material described by Na2Ti9O19 crystallizes in the monoclinic C2/m space group. Na(1) is bonded in a 7-coordinate geometry to one O(9), three equivalent O(5), and three equivalent O(7) atoms. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(1), one O(10), one O(2), one O(4), and two equivalent O(8) atoms. In the second Ti site, Ti(2) is bonded to one O(1), one O(10), one O(3), one O(5), and two equivalent O(6) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 29-41°. In the third Ti site, Ti(3) is bonded to one O(10), one O(2), one O(3), one O(8), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles are 28°. In the fourth Ti site, Ti(4) is bonded to one O(3), one O(6), one O(7), one O(8), and two equivalent O(1) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 31-39°. In the fifth Ti site, Ti(5) is bonded to two equivalent O(5), two equivalent O(7), and two equivalent O(9) atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 0-41°. There are ten inequivalent O sites. In the first O site, O(7) is bonded in a 5-coordinate geometry to three equivalent Na(1), one Ti(4), and one Ti(5) atom. In the second O site, O(8) is bonded to one Ti(3), one Ti(4), and two equivalent Ti(1) atoms to form a mixture of distorted corner and edge-sharing OTi4 trigonal pyramids. In the third O site, O(9) is bonded in a square co-planar geometry to two equivalent Na(1) and two equivalent Ti(5) atoms. In the fourth O site, O(10) is bonded in a 3-coordinate geometry to one Ti(1), one Ti(2), and one Ti(3) atom. In the fifth O site, O(1) is bonded to one Ti(1), one Ti(2), and two equivalent Ti(4) atoms to form a mixture of distorted corner and edge-sharing OTi4 trigonal pyramids. In the sixth O site, O(2) is bonded in a linear geometry to one Ti(1) and one Ti(3) atom. In the seventh O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Ti(2), one Ti(3), and one Ti(4) atom. In the eighth O site, O(4) is bonded in a distorted T-shaped geometry to one Ti(1) and two equivalent Ti(3) atoms. In the ninth O site, O(5) is bonded in a 5-coordinate geometry to three equivalent Na(1), one Ti(2), and one Ti(5) atom. In the tenth O site, O(6) is bonded in a 3-coordinate geometry to one Ti(4) and two equivalent Ti(2) atoms. is represented by the CIF file [CIF]
data_Na2Ti9O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.434
_cell_length_b   6.434
_cell_length_c   15.798
_cell_angle_alpha   75.938
_cell_angle_beta   75.938
_cell_angle_gamma   34.435
_symmetry_Int_Tables_number   1
_cell_volume   357.672
_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
  Na  Na0  1  0.323  0.323  0.492  1.0
  Na  Na1  1  0.677  0.677  0.508  1.0
  Ti  Ti2  1  0.187  0.187  0.882  1.0
  Ti  Ti3  1  0.813  0.813  0.118  1.0
  Ti  Ti4  1  0.915  0.915  0.295  1.0
  Ti  Ti5  1  0.108  0.108  0.118  1.0
  Ti  Ti6  1  0.788  0.788  0.707  1.0
  Ti  Ti7  1  0.000  0.000  0.500  1.0
  Ti  Ti8  1  0.212  0.212  0.293  1.0
  Ti  Ti9  1  0.085  0.085  0.705  1.0
  Ti  Ti10  1  0.892  0.892  0.882  1.0
  O  O11  1  0.249  0.249  0.731  1.0
  O  O12  1  0.126  0.126  0.998  1.0
  O  O13  1  0.073  0.073  0.258  1.0
  O  O14  1  0.352  0.352  0.883  1.0
  O  O15  1  0.927  0.927  0.742  1.0
  O  O16  1  0.874  0.874  0.002  1.0
  O  O17  1  0.648  0.648  0.117  1.0
  O  O18  1  0.900  0.900  0.415  1.0
  O  O19  1  0.376  0.376  0.294  1.0
  O  O20  1  0.751  0.751  0.269  1.0
  O  O21  1  0.152  0.152  0.410  1.0
  O  O22  1  0.272  0.272  0.142  1.0
  O  O23  1  0.728  0.728  0.858  1.0
  O  O24  1  0.624  0.624  0.706  1.0
  O  O25  1  0.500  0.500  0.500  1.0
  O  O26  1  0.951  0.951  0.153  1.0
  O  O27  1  0.049  0.049  0.847  1.0
  O  O28  1  0.100  0.100  0.585  1.0
  O  O29  1  0.848  0.848  0.590  1.0
[/CIF]
.