The compound described by K2TiSi6O15 crystallizes in the monoclinic Cc space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(13), one O(14), one O(2), one O(4), one O(7), and one O(8) atom. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(2), one O(3), one O(5), one O(6), and one O(7) atom. Ti(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), and one O(6) atom to form TiO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(12), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 31°. In the second Si site, Si(2) is bonded to one O(15), one O(6), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the third Si site, Si(3) is bonded to one O(1), one O(14), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. In the fourth Si site, Si(4) is bonded to one O(11), one O(12), one O(15), and one O(2) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. In the fifth Si site, Si(5) is bonded to one O(10), one O(13), one O(14), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. In the sixth Si site, Si(6) is bonded to one O(11), one O(13), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Ti(1), and one Si(3) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Ti(1), and one Si(4) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(2), one Ti(1), and one Si(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one K(1), one Ti(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(2), one Si(1), and one Si(5) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(2), one Ti(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one Si(2), and one Si(6) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one K(1), one Si(1), and one Si(3) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Si(2) and one Si(3) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one K(1), one Ti(1), and one Si(5) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one K(2), one Si(4), and one Si(6) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one K(1), one Si(5), and one Si(6) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one K(1), one Si(3), and one Si(5) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. is represented by the CIF card [CIF]
data_K2Ti(Si2O5)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.251
_cell_length_b   7.251
_cell_length_c   15.159
_cell_angle_alpha   75.762
_cell_angle_beta   75.762
_cell_angle_gamma   59.895
_symmetry_Int_Tables_number   1
_cell_volume   661.067
_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
  K  K0  1  0.821  0.692  0.518  1.0
  K  K1  1  0.692  0.821  0.018  1.0
  K  K2  1  0.472  0.113  0.706  1.0
  K  K3  1  0.113  0.472  0.206  1.0
  Ti  Ti4  1  0.300  0.796  0.633  1.0
  Ti  Ti5  1  0.796  0.300  0.133  1.0
  Si  Si6  1  0.497  0.465  0.472  1.0
  Si  Si7  1  0.465  0.497  0.972  1.0
  Si  Si8  1  0.589  0.036  0.288  1.0
  Si  Si9  1  0.036  0.589  0.788  1.0
  Si  Si10  1  0.298  0.200  0.477  1.0
  Si  Si11  1  0.200  0.298  0.977  1.0
  Si  Si12  1  0.496  0.677  0.268  1.0
  Si  Si13  1  0.677  0.496  0.768  1.0
  Si  Si14  1  0.092  0.954  0.990  1.0
  Si  Si15  1  0.954  0.092  0.490  1.0
  Si  Si16  1  0.023  0.937  0.300  1.0
  Si  Si17  1  0.937  0.023  0.800  1.0
  O  O18  1  0.024  0.374  0.064  1.0
  O  O19  1  0.374  0.024  0.564  1.0
  O  O20  1  0.664  0.573  0.182  1.0
  O  O21  1  0.573  0.664  0.682  1.0
  O  O22  1  0.972  0.159  0.233  1.0
  O  O23  1  0.159  0.972  0.733  1.0
  O  O24  1  0.638  0.457  0.030  1.0
  O  O25  1  0.457  0.638  0.530  1.0
  O  O26  1  0.693  0.230  0.506  1.0
  O  O27  1  0.230  0.693  0.006  1.0
  O  O28  1  0.572  0.232  0.208  1.0
  O  O29  1  0.232  0.572  0.708  1.0
  O  O30  1  0.839  0.864  0.305  1.0
  O  O31  1  0.864  0.839  0.805  1.0
  O  O32  1  0.286  0.426  0.486  1.0
  O  O33  1  0.426  0.286  0.986  1.0
  O  O34  1  0.462  0.122  0.384  1.0
  O  O35  1  0.122  0.462  0.884  1.0
  O  O36  1  0.929  0.031  0.081  1.0
  O  O37  1  0.031  0.929  0.581  1.0
  O  O38  1  0.731  0.248  0.767  1.0
  O  O39  1  0.248  0.731  0.267  1.0
  O  O40  1  0.527  0.571  0.864  1.0
  O  O41  1  0.571  0.527  0.364  1.0
  O  O42  1  0.955  0.026  0.905  1.0
  O  O43  1  0.026  0.955  0.405  1.0
  O  O44  1  0.055  0.261  0.463  1.0
  O  O45  1  0.261  0.055  0.963  1.0
  O  O46  1  0.911  0.481  0.764  1.0
  O  O47  1  0.481  0.911  0.264  1.0
[/CIF]
.
The compound described by K2TiSi6O15 crystallizes in the monoclinic Cc space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(13), one O(14), one O(2), one O(4), one O(7), and one O(8) atom. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(1), one O(11), one O(2), one O(3), one O(5), one O(6), and one O(7) atom. Ti(1) is bonded to one O(1), one O(10), one O(2), one O(3), one O(4), and one O(6) atom to form TiO6 octahedra that share  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra,  a cornercorner with one Si(5)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. There are six inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(12), one O(4), one O(5), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 31°. In the second Si site, Si(2) is bonded to one O(15), one O(6), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(3)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 50°. In the third Si site, Si(3) is bonded to one O(1), one O(14), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. In the fourth Si site, Si(4) is bonded to one O(11), one O(12), one O(15), and one O(2) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. In the fifth Si site, Si(5) is bonded to one O(10), one O(13), one O(14), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(3)O4 tetrahedra, and  a cornercorner with one Si(6)O4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. In the sixth Si site, Si(6) is bonded to one O(11), one O(13), one O(3), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Ti(1)O6 octahedra,  a cornercorner with one Si(2)O4 tetrahedra,  a cornercorner with one Si(4)O4 tetrahedra, and  a cornercorner with one Si(5)O4 tetrahedra. The corner-sharing octahedral tilt angles are 49°. There are fifteen inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Ti(1), and one Si(3) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Ti(1), and one Si(4) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(2), one Ti(1), and one Si(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one K(1), one Ti(1), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(2), one Si(1), and one Si(5) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(2), one Ti(1), and one Si(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one K(1), one K(2), one Si(2), and one Si(6) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one K(1), one Si(1), and one Si(3) atom. In the ninth O site, O(9) is bonded in a linear geometry to one Si(2) and one Si(3) atom. In the tenth O site, O(10) is bonded in a 2-coordinate geometry to one K(1), one Ti(1), and one Si(5) atom. In the eleventh O site, O(11) is bonded in a distorted bent 120 degrees geometry to one K(2), one Si(4), and one Si(6) atom. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(4) atom. In the thirteenth O site, O(13) is bonded in a bent 150 degrees geometry to one K(1), one Si(5), and one Si(6) atom. In the fourteenth O site, O(14) is bonded in a distorted bent 120 degrees geometry to one K(1), one Si(3), and one Si(5) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(4) atom. is represented by the CIF card [CIF]
data_K2Ti(Si2O5)3
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.251
_cell_length_b   7.251
_cell_length_c   15.159
_cell_angle_alpha   75.762
_cell_angle_beta   75.762
_cell_angle_gamma   59.895
_symmetry_Int_Tables_number   1
_cell_volume   661.067
_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
  K  K0  1  0.821  0.692  0.518  1.0
  K  K1  1  0.692  0.821  0.018  1.0
  K  K2  1  0.472  0.113  0.706  1.0
  K  K3  1  0.113  0.472  0.206  1.0
  Ti  Ti4  1  0.300  0.796  0.633  1.0
  Ti  Ti5  1  0.796  0.300  0.133  1.0
  Si  Si6  1  0.497  0.465  0.472  1.0
  Si  Si7  1  0.465  0.497  0.972  1.0
  Si  Si8  1  0.589  0.036  0.288  1.0
  Si  Si9  1  0.036  0.589  0.788  1.0
  Si  Si10  1  0.298  0.200  0.477  1.0
  Si  Si11  1  0.200  0.298  0.977  1.0
  Si  Si12  1  0.496  0.677  0.268  1.0
  Si  Si13  1  0.677  0.496  0.768  1.0
  Si  Si14  1  0.092  0.954  0.990  1.0
  Si  Si15  1  0.954  0.092  0.490  1.0
  Si  Si16  1  0.023  0.937  0.300  1.0
  Si  Si17  1  0.937  0.023  0.800  1.0
  O  O18  1  0.024  0.374  0.064  1.0
  O  O19  1  0.374  0.024  0.564  1.0
  O  O20  1  0.664  0.573  0.182  1.0
  O  O21  1  0.573  0.664  0.682  1.0
  O  O22  1  0.972  0.159  0.233  1.0
  O  O23  1  0.159  0.972  0.733  1.0
  O  O24  1  0.638  0.457  0.030  1.0
  O  O25  1  0.457  0.638  0.530  1.0
  O  O26  1  0.693  0.230  0.506  1.0
  O  O27  1  0.230  0.693  0.006  1.0
  O  O28  1  0.572  0.232  0.208  1.0
  O  O29  1  0.232  0.572  0.708  1.0
  O  O30  1  0.839  0.864  0.305  1.0
  O  O31  1  0.864  0.839  0.805  1.0
  O  O32  1  0.286  0.426  0.486  1.0
  O  O33  1  0.426  0.286  0.986  1.0
  O  O34  1  0.462  0.122  0.384  1.0
  O  O35  1  0.122  0.462  0.884  1.0
  O  O36  1  0.929  0.031  0.081  1.0
  O  O37  1  0.031  0.929  0.581  1.0
  O  O38  1  0.731  0.248  0.767  1.0
  O  O39  1  0.248  0.731  0.267  1.0
  O  O40  1  0.527  0.571  0.864  1.0
  O  O41  1  0.571  0.527  0.364  1.0
  O  O42  1  0.955  0.026  0.905  1.0
  O  O43  1  0.026  0.955  0.405  1.0
  O  O44  1  0.055  0.261  0.463  1.0
  O  O45  1  0.261  0.055  0.963  1.0
  O  O46  1  0.911  0.481  0.764  1.0
  O  O47  1  0.481  0.911  0.264  1.0
[/CIF]
.