The structure described by Ca6Si6O17(OH)2 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), and two equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded to two equivalent O(2), two equivalent O(7), and two equivalent O(8) atoms to form CaO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Ca(3)O6 octahedra. In the third Ca site, Ca(3) is bonded to two equivalent O(1), two equivalent O(7), and two equivalent O(8) atoms to form CaO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Ca(2)O6 octahedra. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(8), and two equivalent O(4) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(10), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra,  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. The corner-sharing octahedral tilt angles are 55°. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-60°. In the third Si site, Si(3) is bonded to one O(3), one O(6), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-61°. H(1) is bonded in a single-bond geometry to one O(1) atom. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(1) is bonded to one Ca(1), one Ca(3), one Ca(4), and one H(1) atom to form distorted OCa3H tetrahedra that share  a cornercorner with one O(1)Ca3H tetrahedra, corners with two equivalent O(2)Ca3Si tetrahedra,  a cornercorner with one O(4)Ca3Si trigonal pyramid,  a cornercorner with one O(8)Ca3Si trigonal pyramid, corners with three equivalent O(3)Ca3Si trigonal pyramids,  an edgeedge with one O(4)Ca3Si trigonal pyramid, and  an edgeedge with one O(8)Ca3Si trigonal pyramid. In the third O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Si(1) atom to form OCa3Si tetrahedra that share  a cornercorner with one O(2)Ca3Si tetrahedra, corners with two equivalent O(1)Ca3H tetrahedra,  a cornercorner with one O(3)Ca3Si trigonal pyramid,  a cornercorner with one O(8)Ca3Si trigonal pyramid, corners with three equivalent O(4)Ca3Si trigonal pyramids,  an edgeedge with one O(3)Ca3Si trigonal pyramid, and  an edgeedge with one O(8)Ca3Si trigonal pyramid. In the fourth O site, O(3) is bonded to one Ca(4), two equivalent Ca(1), and one Si(3) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(2)Ca3Si tetrahedra, corners with three equivalent O(1)Ca3H tetrahedra,  a cornercorner with one O(8)Ca3Si trigonal pyramid, corners with two equivalent O(4)Ca3Si trigonal pyramids,  an edgeedge with one O(2)Ca3Si tetrahedra,  an edgeedge with one O(3)Ca3Si trigonal pyramid, and  an edgeedge with one O(4)Ca3Si trigonal pyramid. In the fifth O site, O(4) is bonded to one Ca(1), two equivalent Ca(4), and one Si(2) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(1)Ca3H tetrahedra, corners with three equivalent O(2)Ca3Si tetrahedra,  a cornercorner with one O(8)Ca3Si trigonal pyramid, corners with two equivalent O(3)Ca3Si trigonal pyramids,  an edgeedge with one O(1)Ca3H tetrahedra,  an edgeedge with one O(3)Ca3Si trigonal pyramid,  an edgeedge with one O(4)Ca3Si trigonal pyramid, and  an edgeedge with one O(8)Ca3Si trigonal pyramid. In the sixth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ca(4), one Si(1), and one Si(2) atom. In the seventh O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Si(1), and one Si(3) atom. In the eighth O site, O(7) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), and one Si(3) atom. In the ninth O site, O(8) is bonded to one Ca(2), one Ca(3), one Ca(4), and one Si(2) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(1)Ca3H tetrahedra,  a cornercorner with one O(2)Ca3Si tetrahedra,  a cornercorner with one O(3)Ca3Si trigonal pyramid,  a cornercorner with one O(4)Ca3Si trigonal pyramid, corners with two equivalent O(8)Ca3Si trigonal pyramids,  an edgeedge with one O(1)Ca3H tetrahedra,  an edgeedge with one O(2)Ca3Si tetrahedra, and  an edgeedge with one O(4)Ca3Si trigonal pyramid. In the tenth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. is represented by the CIF card [CIF]
data_Ca6Si6H2O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.094
_cell_length_b   7.416
_cell_length_c   8.807
_cell_angle_alpha   102.071
_cell_angle_beta   90.097
_cell_angle_gamma   90.083
_symmetry_Int_Tables_number   1
_cell_volume   453.072
_cell_formula_units_Z   1
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  0.656  0.838  0.866  1.0
  Ca  Ca1  1  0.344  0.162  0.134  1.0
  Ca  Ca2  1  0.500  0.000  0.500  1.0
  Ca  Ca3  1  0.500  0.500  0.500  1.0
  Ca  Ca4  1  0.653  0.344  0.856  1.0
  Ca  Ca5  1  0.347  0.656  0.144  1.0
  Si  Si6  1  0.943  0.045  0.682  1.0
  Si  Si7  1  0.057  0.955  0.318  1.0
  Si  Si8  1  0.226  0.365  0.789  1.0
  Si  Si9  1  0.774  0.635  0.211  1.0
  Si  Si10  1  0.229  0.782  0.790  1.0
  Si  Si11  1  0.771  0.218  0.210  1.0
  H  H12  1  0.859  0.550  0.685  1.0
  H  H13  1  0.141  0.450  0.315  1.0
  O  O14  1  0.723  0.554  0.700  1.0
  O  O15  1  0.277  0.446  0.300  1.0
  O  O16  1  0.718  0.049  0.702  1.0
  O  O17  1  0.282  0.951  0.298  1.0
  O  O18  1  0.330  0.859  0.958  1.0
  O  O19  1  0.670  0.141  0.042  1.0
  O  O20  1  0.326  0.368  0.957  1.0
  O  O21  1  0.674  0.632  0.043  1.0
  O  O22  1  0.025  0.247  0.769  1.0
  O  O23  1  0.975  0.753  0.231  1.0
  O  O24  1  0.027  0.891  0.772  1.0
  O  O25  1  0.973  0.109  0.228  1.0
  O  O26  1  0.379  0.787  0.652  1.0
  O  O27  1  0.621  0.213  0.348  1.0
  O  O28  1  0.380  0.292  0.655  1.0
  O  O29  1  0.620  0.708  0.345  1.0
  O  O30  1  0.145  0.572  0.784  1.0
  O  O31  1  0.855  0.428  0.216  1.0
  O  O32  1  0.000  0.000  0.500  1.0
[/CIF]
.
The structure described by Ca6Si6O17(OH)2 crystallizes in the triclinic P-1 space group. There are four inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), and two equivalent O(3) atoms. In the second Ca site, Ca(2) is bonded to two equivalent O(2), two equivalent O(7), and two equivalent O(8) atoms to form CaO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Ca(3)O6 octahedra. In the third Ca site, Ca(3) is bonded to two equivalent O(1), two equivalent O(7), and two equivalent O(8) atoms to form CaO6 octahedra that share corners with two equivalent Si(2)O4 tetrahedra, corners with two equivalent Si(3)O4 tetrahedra, and edges with two equivalent Ca(2)O6 octahedra. In the fourth Ca site, Ca(4) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(8), and two equivalent O(4) atoms. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(10), one O(2), one O(5), and one O(6) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra,  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. The corner-sharing octahedral tilt angles are 55°. In the second Si site, Si(2) is bonded to one O(4), one O(5), one O(8), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-60°. In the third Si site, Si(3) is bonded to one O(3), one O(6), one O(7), and one O(9) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(2)O6 octahedra,  a cornercorner with one Ca(3)O6 octahedra,  a cornercorner with one Si(1)O4 tetrahedra, and  a cornercorner with one Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-61°. H(1) is bonded in a single-bond geometry to one O(1) atom. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a linear geometry to two equivalent Si(1) atoms. In the second O site, O(1) is bonded to one Ca(1), one Ca(3), one Ca(4), and one H(1) atom to form distorted OCa3H tetrahedra that share  a cornercorner with one O(1)Ca3H tetrahedra, corners with two equivalent O(2)Ca3Si tetrahedra,  a cornercorner with one O(4)Ca3Si trigonal pyramid,  a cornercorner with one O(8)Ca3Si trigonal pyramid, corners with three equivalent O(3)Ca3Si trigonal pyramids,  an edgeedge with one O(4)Ca3Si trigonal pyramid, and  an edgeedge with one O(8)Ca3Si trigonal pyramid. In the third O site, O(2) is bonded to one Ca(1), one Ca(2), one Ca(4), and one Si(1) atom to form OCa3Si tetrahedra that share  a cornercorner with one O(2)Ca3Si tetrahedra, corners with two equivalent O(1)Ca3H tetrahedra,  a cornercorner with one O(3)Ca3Si trigonal pyramid,  a cornercorner with one O(8)Ca3Si trigonal pyramid, corners with three equivalent O(4)Ca3Si trigonal pyramids,  an edgeedge with one O(3)Ca3Si trigonal pyramid, and  an edgeedge with one O(8)Ca3Si trigonal pyramid. In the fourth O site, O(3) is bonded to one Ca(4), two equivalent Ca(1), and one Si(3) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(2)Ca3Si tetrahedra, corners with three equivalent O(1)Ca3H tetrahedra,  a cornercorner with one O(8)Ca3Si trigonal pyramid, corners with two equivalent O(4)Ca3Si trigonal pyramids,  an edgeedge with one O(2)Ca3Si tetrahedra,  an edgeedge with one O(3)Ca3Si trigonal pyramid, and  an edgeedge with one O(4)Ca3Si trigonal pyramid. In the fifth O site, O(4) is bonded to one Ca(1), two equivalent Ca(4), and one Si(2) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(1)Ca3H tetrahedra, corners with three equivalent O(2)Ca3Si tetrahedra,  a cornercorner with one O(8)Ca3Si trigonal pyramid, corners with two equivalent O(3)Ca3Si trigonal pyramids,  an edgeedge with one O(1)Ca3H tetrahedra,  an edgeedge with one O(3)Ca3Si trigonal pyramid,  an edgeedge with one O(4)Ca3Si trigonal pyramid, and  an edgeedge with one O(8)Ca3Si trigonal pyramid. In the sixth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Ca(4), one Si(1), and one Si(2) atom. In the seventh O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Ca(1), one Si(1), and one Si(3) atom. In the eighth O site, O(7) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Ca(3), and one Si(3) atom. In the ninth O site, O(8) is bonded to one Ca(2), one Ca(3), one Ca(4), and one Si(2) atom to form distorted OCa3Si trigonal pyramids that share  a cornercorner with one O(1)Ca3H tetrahedra,  a cornercorner with one O(2)Ca3Si tetrahedra,  a cornercorner with one O(3)Ca3Si trigonal pyramid,  a cornercorner with one O(4)Ca3Si trigonal pyramid, corners with two equivalent O(8)Ca3Si trigonal pyramids,  an edgeedge with one O(1)Ca3H tetrahedra,  an edgeedge with one O(2)Ca3Si tetrahedra, and  an edgeedge with one O(4)Ca3Si trigonal pyramid. In the tenth O site, O(9) is bonded in a bent 150 degrees geometry to one Si(2) and one Si(3) atom. is represented by the CIF card [CIF]
data_Ca6Si6H2O19
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.094
_cell_length_b   7.416
_cell_length_c   8.807
_cell_angle_alpha   102.071
_cell_angle_beta   90.097
_cell_angle_gamma   90.083
_symmetry_Int_Tables_number   1
_cell_volume   453.072
_cell_formula_units_Z   1
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  0.656  0.838  0.866  1.0
  Ca  Ca1  1  0.344  0.162  0.134  1.0
  Ca  Ca2  1  0.500  0.000  0.500  1.0
  Ca  Ca3  1  0.500  0.500  0.500  1.0
  Ca  Ca4  1  0.653  0.344  0.856  1.0
  Ca  Ca5  1  0.347  0.656  0.144  1.0
  Si  Si6  1  0.943  0.045  0.682  1.0
  Si  Si7  1  0.057  0.955  0.318  1.0
  Si  Si8  1  0.226  0.365  0.789  1.0
  Si  Si9  1  0.774  0.635  0.211  1.0
  Si  Si10  1  0.229  0.782  0.790  1.0
  Si  Si11  1  0.771  0.218  0.210  1.0
  H  H12  1  0.859  0.550  0.685  1.0
  H  H13  1  0.141  0.450  0.315  1.0
  O  O14  1  0.723  0.554  0.700  1.0
  O  O15  1  0.277  0.446  0.300  1.0
  O  O16  1  0.718  0.049  0.702  1.0
  O  O17  1  0.282  0.951  0.298  1.0
  O  O18  1  0.330  0.859  0.958  1.0
  O  O19  1  0.670  0.141  0.042  1.0
  O  O20  1  0.326  0.368  0.957  1.0
  O  O21  1  0.674  0.632  0.043  1.0
  O  O22  1  0.025  0.247  0.769  1.0
  O  O23  1  0.975  0.753  0.231  1.0
  O  O24  1  0.027  0.891  0.772  1.0
  O  O25  1  0.973  0.109  0.228  1.0
  O  O26  1  0.379  0.787  0.652  1.0
  O  O27  1  0.621  0.213  0.348  1.0
  O  O28  1  0.380  0.292  0.655  1.0
  O  O29  1  0.620  0.708  0.345  1.0
  O  O30  1  0.145  0.572  0.784  1.0
  O  O31  1  0.855  0.428  0.216  1.0
  O  O32  1  0.000  0.000  0.500  1.0
[/CIF]
.