The crystal structure described by NaTi4O8 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded to one O(3), one O(7), and two equivalent O(8) atoms to form distorted NaO4 trigonal pyramids that share  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Ti(3)O6 octahedra, corners with four equivalent Ti(4)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra, and  an edgeedge with one Na(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 28-69°. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 24-52°. In the second Ti site, Ti(2) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(4)O6 octahedra,  a cornercorner with one Na(1)O4 trigonal pyramid,  an edgeedge with one Ti(2)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra,  an edgeedge with one Ti(4)O6 octahedra, and edges with three equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-53°. In the third Ti site, Ti(3) is bonded to one O(1), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form TiO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Na(1)O4 trigonal pyramids,  an edgeedge with one Ti(1)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, edges with two equivalent Ti(4)O6 octahedra, and  an edgeedge with one Na(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 24-53°. In the fourth Ti site, Ti(4) is bonded to one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with four equivalent Na(1)O4 trigonal pyramids,  an edgeedge with one Ti(1)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-52°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ti(2), one Ti(3), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ti(1), one Ti(4), and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded in a distorted tetrahedral geometry to one Na(1), one Ti(2), one Ti(3), and one Ti(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Ti(1), one Ti(3), and one Ti(4) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Ti(1), one Ti(2), and one Ti(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ti(1), one Ti(2), and one Ti(4) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Na(1), one Ti(3), and one Ti(4) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ti(3), and one Ti(4) atom. is represented by the CIF card [CIF]
data_NaTi4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.311
_cell_length_b   5.938
_cell_length_c   11.352
_cell_angle_alpha   58.681
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   651.402
_cell_formula_units_Z   4
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  0.426  0.751  0.901  1.0
  Na  Na1  1  0.926  0.249  0.599  1.0
  Na  Na2  1  0.074  0.751  0.401  1.0
  Na  Na3  1  0.574  0.249  0.099  1.0
  Ti  Ti4  1  0.875  0.894  0.984  1.0
  Ti  Ti5  1  0.877  0.393  0.979  1.0
  Ti  Ti6  1  0.670  0.868  0.757  1.0
  Ti  Ti7  1  0.654  0.361  0.765  1.0
  Ti  Ti8  1  0.170  0.132  0.743  1.0
  Ti  Ti9  1  0.154  0.639  0.735  1.0
  Ti  Ti10  1  0.377  0.607  0.521  1.0
  Ti  Ti11  1  0.375  0.106  0.516  1.0
  Ti  Ti12  1  0.623  0.393  0.479  1.0
  Ti  Ti13  1  0.625  0.894  0.484  1.0
  Ti  Ti14  1  0.830  0.868  0.257  1.0
  Ti  Ti15  1  0.846  0.361  0.265  1.0
  Ti  Ti16  1  0.346  0.639  0.235  1.0
  Ti  Ti17  1  0.330  0.132  0.243  1.0
  Ti  Ti18  1  0.123  0.607  0.021  1.0
  Ti  Ti19  1  0.125  0.106  0.016  1.0
  O  O20  1  0.042  0.972  0.902  1.0
  O  O21  1  0.041  0.473  0.901  1.0
  O  O22  1  0.231  0.756  0.867  1.0
  O  O23  1  0.229  0.262  0.864  1.0
  O  O24  1  0.812  0.758  0.870  1.0
  O  O25  1  0.806  0.249  0.873  1.0
  O  O26  1  0.591  0.025  0.846  1.0
  O  O27  1  0.592  0.530  0.853  1.0
  O  O28  1  0.091  0.975  0.654  1.0
  O  O29  1  0.092  0.470  0.647  1.0
  O  O30  1  0.312  0.242  0.630  1.0
  O  O31  1  0.306  0.751  0.627  1.0
  O  O32  1  0.731  0.244  0.633  1.0
  O  O33  1  0.729  0.738  0.636  1.0
  O  O34  1  0.542  0.028  0.598  1.0
  O  O35  1  0.541  0.527  0.599  1.0
  O  O36  1  0.459  0.473  0.401  1.0
  O  O37  1  0.458  0.972  0.402  1.0
  O  O38  1  0.271  0.262  0.364  1.0
  O  O39  1  0.269  0.756  0.367  1.0
  O  O40  1  0.694  0.249  0.373  1.0
  O  O41  1  0.688  0.758  0.370  1.0
  O  O42  1  0.908  0.530  0.353  1.0
  O  O43  1  0.909  0.025  0.346  1.0
  O  O44  1  0.408  0.470  0.147  1.0
  O  O45  1  0.409  0.975  0.154  1.0
  O  O46  1  0.194  0.751  0.127  1.0
  O  O47  1  0.188  0.242  0.130  1.0
  O  O48  1  0.771  0.738  0.136  1.0
  O  O49  1  0.769  0.244  0.133  1.0
  O  O50  1  0.959  0.527  0.099  1.0
  O  O51  1  0.958  0.028  0.098  1.0
[/CIF]
.
The crystal structure described by NaTi4O8 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded to one O(3), one O(7), and two equivalent O(8) atoms to form distorted NaO4 trigonal pyramids that share  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Ti(3)O6 octahedra, corners with four equivalent Ti(4)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra, and  an edgeedge with one Na(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 28-69°. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 24-52°. In the second Ti site, Ti(2) is bonded to one O(1), one O(3), one O(5), one O(6), and two equivalent O(2) atoms to form TiO6 octahedra that share  a cornercorner with one Ti(3)O6 octahedra, corners with two equivalent Ti(4)O6 octahedra,  a cornercorner with one Na(1)O4 trigonal pyramid,  an edgeedge with one Ti(2)O6 octahedra,  an edgeedge with one Ti(3)O6 octahedra,  an edgeedge with one Ti(4)O6 octahedra, and edges with three equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-53°. In the third Ti site, Ti(3) is bonded to one O(1), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form TiO6 octahedra that share  a cornercorner with one Ti(2)O6 octahedra, corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Na(1)O4 trigonal pyramids,  an edgeedge with one Ti(1)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, edges with two equivalent Ti(4)O6 octahedra, and  an edgeedge with one Na(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles range from 24-53°. In the fourth Ti site, Ti(4) is bonded to one O(2), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form TiO6 octahedra that share  a cornercorner with one Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with four equivalent Na(1)O4 trigonal pyramids,  an edgeedge with one Ti(1)O6 octahedra,  an edgeedge with one Ti(2)O6 octahedra, and edges with two equivalent Ti(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-52°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Ti(2), one Ti(3), and two equivalent Ti(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Ti(1), one Ti(4), and two equivalent Ti(2) atoms. In the third O site, O(3) is bonded in a distorted tetrahedral geometry to one Na(1), one Ti(2), one Ti(3), and one Ti(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Ti(1), one Ti(3), and one Ti(4) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Ti(1), one Ti(2), and one Ti(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ti(1), one Ti(2), and one Ti(4) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Na(1), one Ti(3), and one Ti(4) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ti(3), and one Ti(4) atom. is represented by the CIF card [CIF]
data_NaTi4O8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.311
_cell_length_b   5.938
_cell_length_c   11.352
_cell_angle_alpha   58.681
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   651.402
_cell_formula_units_Z   4
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  0.426  0.751  0.901  1.0
  Na  Na1  1  0.926  0.249  0.599  1.0
  Na  Na2  1  0.074  0.751  0.401  1.0
  Na  Na3  1  0.574  0.249  0.099  1.0
  Ti  Ti4  1  0.875  0.894  0.984  1.0
  Ti  Ti5  1  0.877  0.393  0.979  1.0
  Ti  Ti6  1  0.670  0.868  0.757  1.0
  Ti  Ti7  1  0.654  0.361  0.765  1.0
  Ti  Ti8  1  0.170  0.132  0.743  1.0
  Ti  Ti9  1  0.154  0.639  0.735  1.0
  Ti  Ti10  1  0.377  0.607  0.521  1.0
  Ti  Ti11  1  0.375  0.106  0.516  1.0
  Ti  Ti12  1  0.623  0.393  0.479  1.0
  Ti  Ti13  1  0.625  0.894  0.484  1.0
  Ti  Ti14  1  0.830  0.868  0.257  1.0
  Ti  Ti15  1  0.846  0.361  0.265  1.0
  Ti  Ti16  1  0.346  0.639  0.235  1.0
  Ti  Ti17  1  0.330  0.132  0.243  1.0
  Ti  Ti18  1  0.123  0.607  0.021  1.0
  Ti  Ti19  1  0.125  0.106  0.016  1.0
  O  O20  1  0.042  0.972  0.902  1.0
  O  O21  1  0.041  0.473  0.901  1.0
  O  O22  1  0.231  0.756  0.867  1.0
  O  O23  1  0.229  0.262  0.864  1.0
  O  O24  1  0.812  0.758  0.870  1.0
  O  O25  1  0.806  0.249  0.873  1.0
  O  O26  1  0.591  0.025  0.846  1.0
  O  O27  1  0.592  0.530  0.853  1.0
  O  O28  1  0.091  0.975  0.654  1.0
  O  O29  1  0.092  0.470  0.647  1.0
  O  O30  1  0.312  0.242  0.630  1.0
  O  O31  1  0.306  0.751  0.627  1.0
  O  O32  1  0.731  0.244  0.633  1.0
  O  O33  1  0.729  0.738  0.636  1.0
  O  O34  1  0.542  0.028  0.598  1.0
  O  O35  1  0.541  0.527  0.599  1.0
  O  O36  1  0.459  0.473  0.401  1.0
  O  O37  1  0.458  0.972  0.402  1.0
  O  O38  1  0.271  0.262  0.364  1.0
  O  O39  1  0.269  0.756  0.367  1.0
  O  O40  1  0.694  0.249  0.373  1.0
  O  O41  1  0.688  0.758  0.370  1.0
  O  O42  1  0.908  0.530  0.353  1.0
  O  O43  1  0.909  0.025  0.346  1.0
  O  O44  1  0.408  0.470  0.147  1.0
  O  O45  1  0.409  0.975  0.154  1.0
  O  O46  1  0.194  0.751  0.127  1.0
  O  O47  1  0.188  0.242  0.130  1.0
  O  O48  1  0.771  0.738  0.136  1.0
  O  O49  1  0.769  0.244  0.133  1.0
  O  O50  1  0.959  0.527  0.099  1.0
  O  O51  1  0.958  0.028  0.098  1.0
[/CIF]
.