The crystal structure described by Na2TiSi4O11 crystallizes in the tetragonal I4/m space group. Na(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(2), and four equivalent O(1) atoms. Ti(1) is bonded to one O(4), one O(5), and four equivalent O(1) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with four equivalent Si(1)O4 tetrahedra. The corner-sharing octahedra are not tilted. Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra and corners with three equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. There are five inequivalent O sites. In the first O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(4) is bonded in an octahedral geometry to four equivalent Na(1) and two equivalent Ti(1) atoms. In the third O site, O(5) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ti(1), and one Si(1) atom. In the fifth O site, O(2) is bonded in a 3-coordinate geometry to one Na(1) and two equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2TiSi4O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.652
_cell_length_b   8.652
_cell_length_c   8.652
_cell_angle_alpha   102.034
_cell_angle_beta   102.034
_cell_angle_gamma   125.664
_symmetry_Int_Tables_number   1
_cell_volume   468.193
_cell_formula_units_Z   2
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  0.366  0.317  0.684  1.0
  Na  Na1  1  0.317  0.634  0.951  1.0
  Na  Na2  1  0.634  0.683  0.316  1.0
  Na  Na3  1  0.683  0.366  0.049  1.0
  Ti  Ti4  1  0.756  0.756  0.000  1.0
  Ti  Ti5  1  0.244  0.244  0.000  1.0
  Si  Si6  1  0.499  0.795  0.679  1.0
  Si  Si7  1  0.501  0.205  0.321  1.0
  Si  Si8  1  0.205  0.884  0.704  1.0
  Si  Si9  1  0.884  0.180  0.679  1.0
  Si  Si10  1  0.180  0.501  0.296  1.0
  Si  Si11  1  0.820  0.499  0.704  1.0
  Si  Si12  1  0.116  0.820  0.321  1.0
  Si  Si13  1  0.795  0.116  0.296  1.0
  O  O14  1  0.554  0.682  0.773  1.0
  O  O15  1  0.408  0.678  0.466  1.0
  O  O16  1  0.446  0.318  0.227  1.0
  O  O17  1  0.058  0.592  0.269  1.0
  O  O18  1  0.219  0.446  0.128  1.0
  O  O19  1  0.304  0.958  0.262  1.0
  O  O20  1  0.781  0.554  0.872  1.0
  O  O21  1  0.318  0.091  0.872  1.0
  O  O22  1  0.678  0.211  0.269  1.0
  O  O23  1  0.322  0.789  0.731  1.0
  O  O24  1  0.696  0.042  0.738  1.0
  O  O25  1  0.042  0.304  0.346  1.0
  O  O26  1  0.500  0.500  0.000  1.0
  O  O27  1  0.789  0.058  0.466  1.0
  O  O28  1  0.211  0.942  0.534  1.0
  O  O29  1  0.909  0.781  0.227  1.0
  O  O30  1  0.091  0.219  0.773  1.0
  O  O31  1  0.958  0.696  0.654  1.0
  O  O32  1  0.682  0.909  0.128  1.0
  O  O33  1  0.592  0.322  0.534  1.0
  O  O34  1  0.000  0.000  0.000  1.0
  O  O35  1  0.942  0.408  0.731  1.0
[/CIF]
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The crystal structure described by Na2TiSi4O11 crystallizes in the tetragonal I4/m space group. Na(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(2), and four equivalent O(1) atoms. Ti(1) is bonded to one O(4), one O(5), and four equivalent O(1) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with four equivalent Si(1)O4 tetrahedra. The corner-sharing octahedra are not tilted. Si(1) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra and corners with three equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 41°. There are five inequivalent O sites. In the first O site, O(3) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the second O site, O(4) is bonded in an octahedral geometry to four equivalent Na(1) and two equivalent Ti(1) atoms. In the third O site, O(5) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Ti(1), and one Si(1) atom. In the fifth O site, O(2) is bonded in a 3-coordinate geometry to one Na(1) and two equivalent Si(1) atoms. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2TiSi4O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.652
_cell_length_b   8.652
_cell_length_c   8.652
_cell_angle_alpha   102.034
_cell_angle_beta   102.034
_cell_angle_gamma   125.664
_symmetry_Int_Tables_number   1
_cell_volume   468.193
_cell_formula_units_Z   2
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  0.366  0.317  0.684  1.0
  Na  Na1  1  0.317  0.634  0.951  1.0
  Na  Na2  1  0.634  0.683  0.316  1.0
  Na  Na3  1  0.683  0.366  0.049  1.0
  Ti  Ti4  1  0.756  0.756  0.000  1.0
  Ti  Ti5  1  0.244  0.244  0.000  1.0
  Si  Si6  1  0.499  0.795  0.679  1.0
  Si  Si7  1  0.501  0.205  0.321  1.0
  Si  Si8  1  0.205  0.884  0.704  1.0
  Si  Si9  1  0.884  0.180  0.679  1.0
  Si  Si10  1  0.180  0.501  0.296  1.0
  Si  Si11  1  0.820  0.499  0.704  1.0
  Si  Si12  1  0.116  0.820  0.321  1.0
  Si  Si13  1  0.795  0.116  0.296  1.0
  O  O14  1  0.554  0.682  0.773  1.0
  O  O15  1  0.408  0.678  0.466  1.0
  O  O16  1  0.446  0.318  0.227  1.0
  O  O17  1  0.058  0.592  0.269  1.0
  O  O18  1  0.219  0.446  0.128  1.0
  O  O19  1  0.304  0.958  0.262  1.0
  O  O20  1  0.781  0.554  0.872  1.0
  O  O21  1  0.318  0.091  0.872  1.0
  O  O22  1  0.678  0.211  0.269  1.0
  O  O23  1  0.322  0.789  0.731  1.0
  O  O24  1  0.696  0.042  0.738  1.0
  O  O25  1  0.042  0.304  0.346  1.0
  O  O26  1  0.500  0.500  0.000  1.0
  O  O27  1  0.789  0.058  0.466  1.0
  O  O28  1  0.211  0.942  0.534  1.0
  O  O29  1  0.909  0.781  0.227  1.0
  O  O30  1  0.091  0.219  0.773  1.0
  O  O31  1  0.958  0.696  0.654  1.0
  O  O32  1  0.682  0.909  0.128  1.0
  O  O33  1  0.592  0.322  0.534  1.0
  O  O34  1  0.000  0.000  0.000  1.0
  O  O35  1  0.942  0.408  0.731  1.0
[/CIF]
.