The structure described by (Ca4Si6O19)2(O2)3 crystallizes in the monoclinic Cm space group. The structure consists of two trioxidane molecules inside a Ca4Si6O19 framework. In the Ca4Si6O19 framework, there are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(10), one O(7), one O(9), two equivalent O(3), and two equivalent O(4) atoms. In the second Ca site, Ca(2) is bonded to one O(3), one O(4), one O(6), two equivalent O(10), and two equivalent O(9) atoms to form distorted CaO7 hexagonal pyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, edges with two equivalent Ca(2)O7 hexagonal pyramids, and  an edgeedge with one Si(3)O4 tetrahedra. There are three 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 Ca(2)O7 hexagonal pyramids,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O7 hexagonal pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(10), one O(2), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(2)O7 hexagonal pyramids,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  an edgeedge with one Ca(2)O7 hexagonal pyramid. There are ten inequivalent O sites. In the first O site, O(8) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the second O site, O(9) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Ca(2), and one Si(3) atom. In the third O site, O(10) is bonded to one Ca(1), two equivalent Ca(2), and one Si(3) atom to form distorted corner-sharing OCa3Si tetrahedra. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the sixth O site, O(3) is bonded to one Ca(2), two equivalent Ca(1), and one Si(1) atom to form distorted corner-sharing OCa3Si tetrahedra. In the seventh O site, O(4) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(1), and one Si(1) atom. In the eighth O site, O(5) is bonded in a linear geometry to two equivalent Si(2) atoms. In the ninth O site, O(6) is bonded in a bent 120 degrees geometry to one Ca(2) and one Si(2) atom. In the tenth O site, O(7) is bonded in a single-bond geometry to one Ca(1) atom. is represented by the CIF card [CIF]
data_Ca2Si3O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.895
_cell_length_b   11.895
_cell_length_c   6.734
_cell_angle_alpha   83.862
_cell_angle_beta   83.862
_cell_angle_gamma   146.999
_symmetry_Int_Tables_number   1
_cell_volume   480.718
_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
  Ca  Ca0  1  0.372  0.956  0.564  1.0
  Ca  Ca1  1  0.956  0.372  0.564  1.0
  Ca  Ca2  1  0.471  0.876  0.074  1.0
  Ca  Ca3  1  0.876  0.471  0.074  1.0
  Si  Si4  1  0.777  0.465  0.610  1.0
  Si  Si5  1  0.465  0.777  0.610  1.0
  Si  Si6  1  0.913  0.772  0.240  1.0
  Si  Si7  1  0.772  0.913  0.240  1.0
  Si  Si8  1  0.364  0.049  0.027  1.0
  Si  Si9  1  0.049  0.364  0.027  1.0
  O  O10  1  0.820  0.631  0.485  1.0
  O  O11  1  0.631  0.820  0.485  1.0
  O  O12  1  0.543  0.275  0.815  1.0
  O  O13  1  0.275  0.543  0.815  1.0
  O  O14  1  0.747  0.346  0.461  1.0
  O  O15  1  0.346  0.747  0.461  1.0
  O  O16  1  0.977  0.594  0.691  1.0
  O  O17  1  0.594  0.977  0.691  1.0
  O  O18  1  0.859  0.859  0.246  1.0
  O  O19  1  0.796  0.601  0.112  1.0
  O  O20  1  0.601  0.796  0.112  1.0
  O  O21  1  0.269  0.072  0.571  1.0
  O  O22  1  0.072  0.269  0.571  1.0
  O  O23  1  0.181  0.986  0.140  1.0
  O  O24  1  0.986  0.181  0.140  1.0
  O  O25  1  0.486  0.097  0.185  1.0
  O  O26  1  0.097  0.486  0.185  1.0
  O  O27  1  0.259  0.857  0.949  1.0
  O  O28  1  0.857  0.259  0.949  1.0
  O  O29  1  0.705  0.705  0.819  1.0
  O  O30  1  0.499  0.499  0.906  1.0
  O  O31  1  0.411  0.411  0.110  1.0
[/CIF]
.
The structure described by (Ca4Si6O19)2(O2)3 crystallizes in the monoclinic Cm space group. The structure consists of two trioxidane molecules inside a Ca4Si6O19 framework. In the Ca4Si6O19 framework, there are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(10), one O(7), one O(9), two equivalent O(3), and two equivalent O(4) atoms. In the second Ca site, Ca(2) is bonded to one O(3), one O(4), one O(6), two equivalent O(10), and two equivalent O(9) atoms to form distorted CaO7 hexagonal pyramids that share  a cornercorner with one Si(2)O4 tetrahedra, corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, edges with two equivalent Ca(2)O7 hexagonal pyramids, and  an edgeedge with one Si(3)O4 tetrahedra. There are three 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 Ca(2)O7 hexagonal pyramids,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(1), one O(5), one O(6), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O7 hexagonal pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. In the third Si site, Si(3) is bonded to one O(10), one O(2), one O(8), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(2)O7 hexagonal pyramids,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and  an edgeedge with one Ca(2)O7 hexagonal pyramid. There are ten inequivalent O sites. In the first O site, O(8) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. In the second O site, O(9) is bonded in a 4-coordinate geometry to one Ca(1), two equivalent Ca(2), and one Si(3) atom. In the third O site, O(10) is bonded to one Ca(1), two equivalent Ca(2), and one Si(3) atom to form distorted corner-sharing OCa3Si tetrahedra. In the fourth O site, O(1) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the fifth O site, O(2) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(3) atom. In the sixth O site, O(3) is bonded to one Ca(2), two equivalent Ca(1), and one Si(1) atom to form distorted corner-sharing OCa3Si tetrahedra. In the seventh O site, O(4) is bonded in a 4-coordinate geometry to one Ca(2), two equivalent Ca(1), and one Si(1) atom. In the eighth O site, O(5) is bonded in a linear geometry to two equivalent Si(2) atoms. In the ninth O site, O(6) is bonded in a bent 120 degrees geometry to one Ca(2) and one Si(2) atom. In the tenth O site, O(7) is bonded in a single-bond geometry to one Ca(1) atom. is represented by the CIF card [CIF]
data_Ca2Si3O11
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.895
_cell_length_b   11.895
_cell_length_c   6.734
_cell_angle_alpha   83.862
_cell_angle_beta   83.862
_cell_angle_gamma   146.999
_symmetry_Int_Tables_number   1
_cell_volume   480.718
_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
  Ca  Ca0  1  0.372  0.956  0.564  1.0
  Ca  Ca1  1  0.956  0.372  0.564  1.0
  Ca  Ca2  1  0.471  0.876  0.074  1.0
  Ca  Ca3  1  0.876  0.471  0.074  1.0
  Si  Si4  1  0.777  0.465  0.610  1.0
  Si  Si5  1  0.465  0.777  0.610  1.0
  Si  Si6  1  0.913  0.772  0.240  1.0
  Si  Si7  1  0.772  0.913  0.240  1.0
  Si  Si8  1  0.364  0.049  0.027  1.0
  Si  Si9  1  0.049  0.364  0.027  1.0
  O  O10  1  0.820  0.631  0.485  1.0
  O  O11  1  0.631  0.820  0.485  1.0
  O  O12  1  0.543  0.275  0.815  1.0
  O  O13  1  0.275  0.543  0.815  1.0
  O  O14  1  0.747  0.346  0.461  1.0
  O  O15  1  0.346  0.747  0.461  1.0
  O  O16  1  0.977  0.594  0.691  1.0
  O  O17  1  0.594  0.977  0.691  1.0
  O  O18  1  0.859  0.859  0.246  1.0
  O  O19  1  0.796  0.601  0.112  1.0
  O  O20  1  0.601  0.796  0.112  1.0
  O  O21  1  0.269  0.072  0.571  1.0
  O  O22  1  0.072  0.269  0.571  1.0
  O  O23  1  0.181  0.986  0.140  1.0
  O  O24  1  0.986  0.181  0.140  1.0
  O  O25  1  0.486  0.097  0.185  1.0
  O  O26  1  0.097  0.486  0.185  1.0
  O  O27  1  0.259  0.857  0.949  1.0
  O  O28  1  0.857  0.259  0.949  1.0
  O  O29  1  0.705  0.705  0.819  1.0
  O  O30  1  0.499  0.499  0.906  1.0
  O  O31  1  0.411  0.411  0.110  1.0
[/CIF]
.