The compound described by Na4Ti7O16 crystallizes in the monoclinic Pm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(10), one O(2), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(2), one O(9), two equivalent O(4), and two equivalent O(7) atoms. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(7), one O(8), and one O(9) atom. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(11), one O(6), two equivalent O(12), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 46-48°. In the second Ti site, Ti(2) is bonded to one O(10), one O(5), two equivalent O(12), and two equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(1), one O(8), two equivalent O(4), and two equivalent O(7) atoms. In the fourth Ti site, Ti(4) is bonded to one O(12), one O(4), one O(5), one O(6), one O(8), and one O(9) atom to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. In the fifth Ti site, Ti(5) is bonded to one O(1), one O(10), one O(11), one O(2), one O(3), and one O(7) atom to form edge-sharing TiO6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ti(3) and two equivalent Ti(5) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), two equivalent Na(3), and two equivalent Ti(5) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Na(1), one Ti(1), one Ti(2), and one Ti(5) atom. In the fourth O site, O(4) is bonded to one Na(2), one Na(3), one Ti(3), and one Ti(4) atom to form distorted ONa2Ti2 trigonal pyramids that share  a cornercorner with one O(8)Na2Ti3 square pyramid,  a cornercorner with one O(9)Na3Ti2 square pyramid, corners with two equivalent O(4)Na2Ti2 trigonal pyramids,  an edgeedge with one O(8)Na2Ti3 square pyramid, and  an edgeedge with one O(9)Na3Ti2 square pyramid. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ti(2) and two equivalent Ti(4) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ti(1) and two equivalent Ti(4) atoms. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Na(2), one Na(3), one Ti(3), and one Ti(5) atom. In the eighth O site, O(8) is bonded to two equivalent Na(3), one Ti(3), and two equivalent Ti(4) atoms to form ONa2Ti3 square pyramids that share corners with two equivalent O(4)Na2Ti2 trigonal pyramids, edges with two equivalent O(9)Na3Ti2 square pyramids, and edges with two equivalent O(4)Na2Ti2 trigonal pyramids. In the ninth O site, O(9) is bonded to one Na(2), two equivalent Na(3), and two equivalent Ti(4) atoms to form ONa3Ti2 square pyramids that share corners with two equivalent O(4)Na2Ti2 trigonal pyramids, edges with two equivalent O(8)Na2Ti3 square pyramids, and edges with two equivalent O(4)Na2Ti2 trigonal pyramids. In the tenth O site, O(10) is bonded in a tetrahedral geometry to one Na(1), one Ti(2), and two equivalent Ti(5) atoms. In the eleventh O site, O(11) is bonded in a trigonal non-coplanar geometry to one Ti(1) and two equivalent Ti(5) atoms. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Ti(1), one Ti(2), and one Ti(4) atom. is represented by the CIF card [CIF]
data_Na4Ti7O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.034
_cell_length_b   5.518
_cell_length_c   9.583
_cell_angle_alpha   88.771
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   319.002
_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  0.500  0.566  0.960  1.0
  Na  Na1  1  0.500  0.527  0.655  1.0
  Na  Na2  1  0.257  0.044  0.544  1.0
  Na  Na3  1  0.743  0.044  0.544  1.0
  Ti  Ti4  1  0.000  0.958  0.136  1.0
  Ti  Ti5  1  0.500  0.994  0.159  1.0
  Ti  Ti6  1  0.000  0.543  0.651  1.0
  Ti  Ti7  1  0.248  0.482  0.360  1.0
  Ti  Ti8  1  0.752  0.482  0.360  1.0
  Ti  Ti9  1  0.253  0.048  0.862  1.0
  Ti  Ti10  1  0.747  0.048  0.862  1.0
  O  O11  1  0.000  0.825  0.766  1.0
  O  O12  1  0.500  0.880  0.774  1.0
  O  O13  1  0.253  0.829  0.041  1.0
  O  O14  1  0.747  0.829  0.041  1.0
  O  O15  1  0.776  0.662  0.524  1.0
  O  O16  1  0.224  0.662  0.524  1.0
  O  O17  1  0.500  0.686  0.272  1.0
  O  O18  1  0.000  0.662  0.264  1.0
  O  O19  1  0.218  0.305  0.736  1.0
  O  O20  1  0.782  0.305  0.736  1.0
  O  O21  1  0.000  0.304  0.452  1.0
  O  O22  1  0.500  0.311  0.439  1.0
  O  O23  1  0.500  0.185  0.970  1.0
  O  O24  1  0.000  0.172  0.969  1.0
  O  O25  1  0.249  0.161  0.228  1.0
  O  O26  1  0.751  0.161  0.228  1.0
[/CIF]
.
The compound described by Na4Ti7O16 crystallizes in the monoclinic Pm space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(10), one O(2), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(2), one O(9), two equivalent O(4), and two equivalent O(7) atoms. In the third Na site, Na(3) is bonded in a 4-coordinate geometry to one O(2), one O(4), one O(7), one O(8), and one O(9) atom. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(11), one O(6), two equivalent O(12), and two equivalent O(3) atoms to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 46-48°. In the second Ti site, Ti(2) is bonded to one O(10), one O(5), two equivalent O(12), and two equivalent O(3) atoms to form a mixture of distorted corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 48-53°. In the third Ti site, Ti(3) is bonded in a 6-coordinate geometry to one O(1), one O(8), two equivalent O(4), and two equivalent O(7) atoms. In the fourth Ti site, Ti(4) is bonded to one O(12), one O(4), one O(5), one O(6), one O(8), and one O(9) atom to form a mixture of corner and edge-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. In the fifth Ti site, Ti(5) is bonded to one O(1), one O(10), one O(11), one O(2), one O(3), and one O(7) atom to form edge-sharing TiO6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ti(3) and two equivalent Ti(5) atoms. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), one Na(2), two equivalent Na(3), and two equivalent Ti(5) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Na(1), one Ti(1), one Ti(2), and one Ti(5) atom. In the fourth O site, O(4) is bonded to one Na(2), one Na(3), one Ti(3), and one Ti(4) atom to form distorted ONa2Ti2 trigonal pyramids that share  a cornercorner with one O(8)Na2Ti3 square pyramid,  a cornercorner with one O(9)Na3Ti2 square pyramid, corners with two equivalent O(4)Na2Ti2 trigonal pyramids,  an edgeedge with one O(8)Na2Ti3 square pyramid, and  an edgeedge with one O(9)Na3Ti2 square pyramid. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ti(2) and two equivalent Ti(4) atoms. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ti(1) and two equivalent Ti(4) atoms. In the seventh O site, O(7) is bonded in a rectangular see-saw-like geometry to one Na(2), one Na(3), one Ti(3), and one Ti(5) atom. In the eighth O site, O(8) is bonded to two equivalent Na(3), one Ti(3), and two equivalent Ti(4) atoms to form ONa2Ti3 square pyramids that share corners with two equivalent O(4)Na2Ti2 trigonal pyramids, edges with two equivalent O(9)Na3Ti2 square pyramids, and edges with two equivalent O(4)Na2Ti2 trigonal pyramids. In the ninth O site, O(9) is bonded to one Na(2), two equivalent Na(3), and two equivalent Ti(4) atoms to form ONa3Ti2 square pyramids that share corners with two equivalent O(4)Na2Ti2 trigonal pyramids, edges with two equivalent O(8)Na2Ti3 square pyramids, and edges with two equivalent O(4)Na2Ti2 trigonal pyramids. In the tenth O site, O(10) is bonded in a tetrahedral geometry to one Na(1), one Ti(2), and two equivalent Ti(5) atoms. In the eleventh O site, O(11) is bonded in a trigonal non-coplanar geometry to one Ti(1) and two equivalent Ti(5) atoms. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one Ti(1), one Ti(2), and one Ti(4) atom. is represented by the CIF card [CIF]
data_Na4Ti7O16
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.034
_cell_length_b   5.518
_cell_length_c   9.583
_cell_angle_alpha   88.771
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   319.002
_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  0.500  0.566  0.960  1.0
  Na  Na1  1  0.500  0.527  0.655  1.0
  Na  Na2  1  0.257  0.044  0.544  1.0
  Na  Na3  1  0.743  0.044  0.544  1.0
  Ti  Ti4  1  0.000  0.958  0.136  1.0
  Ti  Ti5  1  0.500  0.994  0.159  1.0
  Ti  Ti6  1  0.000  0.543  0.651  1.0
  Ti  Ti7  1  0.248  0.482  0.360  1.0
  Ti  Ti8  1  0.752  0.482  0.360  1.0
  Ti  Ti9  1  0.253  0.048  0.862  1.0
  Ti  Ti10  1  0.747  0.048  0.862  1.0
  O  O11  1  0.000  0.825  0.766  1.0
  O  O12  1  0.500  0.880  0.774  1.0
  O  O13  1  0.253  0.829  0.041  1.0
  O  O14  1  0.747  0.829  0.041  1.0
  O  O15  1  0.776  0.662  0.524  1.0
  O  O16  1  0.224  0.662  0.524  1.0
  O  O17  1  0.500  0.686  0.272  1.0
  O  O18  1  0.000  0.662  0.264  1.0
  O  O19  1  0.218  0.305  0.736  1.0
  O  O20  1  0.782  0.305  0.736  1.0
  O  O21  1  0.000  0.304  0.452  1.0
  O  O22  1  0.500  0.311  0.439  1.0
  O  O23  1  0.500  0.185  0.970  1.0
  O  O24  1  0.000  0.172  0.969  1.0
  O  O25  1  0.249  0.161  0.228  1.0
  O  O26  1  0.751  0.161  0.228  1.0
[/CIF]
.