The material described by Na2TiSi4H4O13 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(7) atom. Ti(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form TiO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-41°. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) and one O(7) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(2) atom. In the second O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Ti(1), one Si(2), and one H(1) atom. In the third O site, O(6) is bonded in a linear geometry to two equivalent Si(2) atoms. In the fourth O site, O(7) is bonded in a distorted water-like geometry to one Na(1), one H(1), and one H(2) atom. In the fifth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the sixth O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Ti(1), and one Si(1) atom. In the seventh O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Ti(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2TiSi4H4O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.841
_cell_length_b   7.460
_cell_length_c   9.032
_cell_angle_alpha   67.616
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   550.769
_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  0.191  0.792  0.197  1.0
  Na  Na1  1  0.691  0.708  0.803  1.0
  Na  Na2  1  0.809  0.208  0.803  1.0
  Na  Na3  1  0.309  0.292  0.197  1.0
  Ti  Ti4  1  0.000  0.500  0.000  1.0
  Ti  Ti5  1  0.500  0.000  0.000  1.0
  Si  Si6  1  0.661  0.303  0.160  1.0
  Si  Si7  1  0.161  0.197  0.840  1.0
  Si  Si8  1  0.339  0.697  0.840  1.0
  Si  Si9  1  0.839  0.803  0.160  1.0
  Si  Si10  1  0.941  0.095  0.315  1.0
  Si  Si11  1  0.441  0.405  0.685  1.0
  Si  Si12  1  0.059  0.905  0.685  1.0
  Si  Si13  1  0.559  0.595  0.315  1.0
  H  H14  1  0.104  0.406  0.336  1.0
  H  H15  1  0.604  0.094  0.664  1.0
  H  H16  1  0.896  0.594  0.664  1.0
  H  H17  1  0.396  0.906  0.336  1.0
  H  H18  1  0.194  0.419  0.486  1.0
  H  H19  1  0.694  0.081  0.514  1.0
  H  H20  1  0.806  0.581  0.514  1.0
  H  H21  1  0.306  0.919  0.486  1.0
  O  O22  1  0.760  0.154  0.315  1.0
  O  O23  1  0.260  0.346  0.685  1.0
  O  O24  1  0.240  0.846  0.685  1.0
  O  O25  1  0.740  0.654  0.315  1.0
  O  O26  1  0.537  0.184  0.100  1.0
  O  O27  1  0.037  0.316  0.900  1.0
  O  O28  1  0.463  0.816  0.900  1.0
  O  O29  1  0.963  0.684  0.100  1.0
  O  O30  1  0.779  0.432  0.023  1.0
  O  O31  1  0.279  0.068  0.977  1.0
  O  O32  1  0.221  0.568  0.977  1.0
  O  O33  1  0.721  0.932  0.023  1.0
  O  O34  1  0.552  0.431  0.235  1.0
  O  O35  1  0.052  0.069  0.765  1.0
  O  O36  1  0.448  0.569  0.765  1.0
  O  O37  1  0.948  0.931  0.235  1.0
  O  O38  1  0.037  0.287  0.213  1.0
  O  O39  1  0.537  0.213  0.787  1.0
  O  O40  1  0.963  0.713  0.787  1.0
  O  O41  1  0.463  0.787  0.213  1.0
  O  O42  1  0.500  0.500  0.500  1.0
  O  O43  1  0.000  0.000  0.500  1.0
  O  O44  1  0.186  0.474  0.368  1.0
  O  O45  1  0.686  0.026  0.632  1.0
  O  O46  1  0.814  0.526  0.632  1.0
  O  O47  1  0.314  0.974  0.368  1.0
[/CIF]
.
The material described by Na2TiSi4H4O13 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(7) atom. Ti(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form TiO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra and corners with four equivalent Si(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 32-41°. In the second Si site, Si(2) is bonded to one O(1), one O(4), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) and one O(7) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(7) atom. There are seven inequivalent O sites. In the first O site, O(4) is bonded in a 3-coordinate geometry to one Na(1), one Si(1), and one Si(2) atom. In the second O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Ti(1), one Si(2), and one H(1) atom. In the third O site, O(6) is bonded in a linear geometry to two equivalent Si(2) atoms. In the fourth O site, O(7) is bonded in a distorted water-like geometry to one Na(1), one H(1), and one H(2) atom. In the fifth O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Si(1) and one Si(2) atom. In the sixth O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Ti(1), and one Si(1) atom. In the seventh O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Ti(1), and one Si(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_Na2TiSi4H4O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   8.841
_cell_length_b   7.460
_cell_length_c   9.032
_cell_angle_alpha   67.616
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   550.769
_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  0.191  0.792  0.197  1.0
  Na  Na1  1  0.691  0.708  0.803  1.0
  Na  Na2  1  0.809  0.208  0.803  1.0
  Na  Na3  1  0.309  0.292  0.197  1.0
  Ti  Ti4  1  0.000  0.500  0.000  1.0
  Ti  Ti5  1  0.500  0.000  0.000  1.0
  Si  Si6  1  0.661  0.303  0.160  1.0
  Si  Si7  1  0.161  0.197  0.840  1.0
  Si  Si8  1  0.339  0.697  0.840  1.0
  Si  Si9  1  0.839  0.803  0.160  1.0
  Si  Si10  1  0.941  0.095  0.315  1.0
  Si  Si11  1  0.441  0.405  0.685  1.0
  Si  Si12  1  0.059  0.905  0.685  1.0
  Si  Si13  1  0.559  0.595  0.315  1.0
  H  H14  1  0.104  0.406  0.336  1.0
  H  H15  1  0.604  0.094  0.664  1.0
  H  H16  1  0.896  0.594  0.664  1.0
  H  H17  1  0.396  0.906  0.336  1.0
  H  H18  1  0.194  0.419  0.486  1.0
  H  H19  1  0.694  0.081  0.514  1.0
  H  H20  1  0.806  0.581  0.514  1.0
  H  H21  1  0.306  0.919  0.486  1.0
  O  O22  1  0.760  0.154  0.315  1.0
  O  O23  1  0.260  0.346  0.685  1.0
  O  O24  1  0.240  0.846  0.685  1.0
  O  O25  1  0.740  0.654  0.315  1.0
  O  O26  1  0.537  0.184  0.100  1.0
  O  O27  1  0.037  0.316  0.900  1.0
  O  O28  1  0.463  0.816  0.900  1.0
  O  O29  1  0.963  0.684  0.100  1.0
  O  O30  1  0.779  0.432  0.023  1.0
  O  O31  1  0.279  0.068  0.977  1.0
  O  O32  1  0.221  0.568  0.977  1.0
  O  O33  1  0.721  0.932  0.023  1.0
  O  O34  1  0.552  0.431  0.235  1.0
  O  O35  1  0.052  0.069  0.765  1.0
  O  O36  1  0.448  0.569  0.765  1.0
  O  O37  1  0.948  0.931  0.235  1.0
  O  O38  1  0.037  0.287  0.213  1.0
  O  O39  1  0.537  0.213  0.787  1.0
  O  O40  1  0.963  0.713  0.787  1.0
  O  O41  1  0.463  0.787  0.213  1.0
  O  O42  1  0.500  0.500  0.500  1.0
  O  O43  1  0.000  0.000  0.500  1.0
  O  O44  1  0.186  0.474  0.368  1.0
  O  O45  1  0.686  0.026  0.632  1.0
  O  O46  1  0.814  0.526  0.632  1.0
  O  O47  1  0.314  0.974  0.368  1.0
[/CIF]
.