The structure described by Ca6Si3H2O13 crystallizes in the triclinic P-1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(12), one O(13), one O(5), one O(7), and one O(9) atom to form distorted CaO6 octahedra that share corners with two equivalent Si(3)O4 tetrahedra and corners with three equivalent Si(1)O4 tetrahedra. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(11), one O(2), one O(6), one O(9), and two equivalent O(10) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one H(1), one O(1), one O(10), one O(11), one O(4), one O(5), one O(6), and one O(9) atom. In the fourth Ca site, Ca(4) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(9) atom. In the fifth Ca site, Ca(5) is bonded in a 8-coordinate geometry to one H(1), one O(1), one O(12), one O(3), one O(6), one O(8), and two equivalent O(13) atoms. In the sixth Ca site, Ca(6) is bonded in a 7-coordinate geometry to one O(11), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(12), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-66°. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(10), one O(11), one O(2), and one O(4) atom. In the third Si site, Si(3) is bonded to one O(13), one O(3), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-68°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one Ca(3), one Ca(5), and one O(6) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(9) atom. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(3), one Ca(4), one Ca(5), and one Si(1) atom. In the second O site, O(2) is bonded to one Ca(2), one Ca(4), one Ca(6), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the third O site, O(3) is bonded to one Ca(4), one Ca(5), one Ca(6), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the fourth O site, O(4) is bonded to one Ca(3), one Ca(4), one Ca(6), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(3), one Ca(6), and one Si(3) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ca(2), one Ca(3), one Ca(5), one Ca(6), and one H(1) atom. In the seventh O site, O(7) is bonded to one Ca(1), one Ca(4), one Ca(6), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ca(5), one Si(1), and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), one Ca(3), one Ca(4), and one H(2) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Ca(3), two equivalent Ca(2), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Ca(6), and one Si(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Ca(5), and one Si(1) atom. In the thirteenth O site, O(13) is bonded to one Ca(1), two equivalent Ca(5), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. is represented by the CIF file [CIF]
data_Ca6Si3H2O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.893
_cell_length_b   7.006
_cell_length_c   12.985
_cell_angle_alpha   90.800
_cell_angle_beta   97.633
_cell_angle_gamma   98.053
_symmetry_Int_Tables_number   1
_cell_volume   615.038
_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  0.684  0.808  0.124  1.0
  Ca  Ca1  1  0.810  0.796  0.512  1.0
  Ca  Ca2  1  0.440  0.967  0.679  1.0
  Ca  Ca3  1  0.107  0.528  0.709  1.0
  Ca  Ca4  1  0.919  0.805  0.898  1.0
  Ca  Ca5  1  0.081  0.195  0.102  1.0
  Ca  Ca6  1  0.190  0.204  0.488  1.0
  Ca  Ca7  1  0.893  0.472  0.291  1.0
  Ca  Ca8  1  0.406  0.523  0.297  1.0
  Ca  Ca9  1  0.560  0.033  0.321  1.0
  Ca  Ca10  1  0.594  0.477  0.703  1.0
  Ca  Ca11  1  0.316  0.192  0.876  1.0
  Si  Si12  1  0.386  0.711  0.902  1.0
  Si  Si13  1  0.614  0.289  0.098  1.0
  Si  Si14  1  0.285  0.701  0.491  1.0
  Si  Si15  1  0.810  0.285  0.884  1.0
  Si  Si16  1  0.190  0.715  0.116  1.0
  Si  Si17  1  0.715  0.299  0.509  1.0
  H  H18  1  0.188  0.028  0.277  1.0
  H  H19  1  0.066  0.118  0.677  1.0
  H  H20  1  0.812  0.972  0.723  1.0
  H  H21  1  0.934  0.882  0.323  1.0
  O  O22  1  0.743  0.151  0.176  1.0
  O  O23  1  0.834  0.485  0.582  1.0
  O  O24  1  0.885  0.489  0.831  1.0
  O  O25  1  0.358  0.633  0.610  1.0
  O  O26  1  0.617  0.185  0.805  1.0
  O  O27  1  0.765  0.839  0.698  1.0
  O  O28  1  0.642  0.367  0.390  1.0
  O  O29  1  0.619  0.489  0.166  1.0
  O  O30  1  0.252  0.664  1.000  1.0
  O  O31  1  0.383  0.815  0.195  1.0
  O  O32  1  0.381  0.511  0.834  1.0
  O  O33  1  0.810  0.793  0.315  1.0
  O  O34  1  0.166  0.515  0.418  1.0
  O  O35  1  0.748  0.336  0.000  1.0
  O  O36  1  0.847  0.128  0.489  1.0
  O  O37  1  0.235  0.161  0.302  1.0
  O  O38  1  0.257  0.849  0.824  1.0
  O  O39  1  0.190  0.207  0.685  1.0
  O  O40  1  0.521  0.218  0.567  1.0
  O  O41  1  0.610  0.806  0.947  1.0
  O  O42  1  0.479  0.782  0.433  1.0
  O  O43  1  0.014  0.851  0.090  1.0
  O  O44  1  0.986  0.149  0.910  1.0
  O  O45  1  0.115  0.511  0.169  1.0
  O  O46  1  0.153  0.872  0.511  1.0
  O  O47  1  0.390  0.194  0.053  1.0
[/CIF]
.
The structure described by Ca6Si3H2O13 crystallizes in the triclinic P-1 space group. There are six inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(12), one O(13), one O(5), one O(7), and one O(9) atom to form distorted CaO6 octahedra that share corners with two equivalent Si(3)O4 tetrahedra and corners with three equivalent Si(1)O4 tetrahedra. In the second Ca site, Ca(2) is bonded in a 6-coordinate geometry to one O(11), one O(2), one O(6), one O(9), and two equivalent O(10) atoms. In the third Ca site, Ca(3) is bonded in a 8-coordinate geometry to one H(1), one O(1), one O(10), one O(11), one O(4), one O(5), one O(6), and one O(9) atom. In the fourth Ca site, Ca(4) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(7), and one O(9) atom. In the fifth Ca site, Ca(5) is bonded in a 8-coordinate geometry to one H(1), one O(1), one O(12), one O(3), one O(6), one O(8), and two equivalent O(13) atoms. In the sixth Ca site, Ca(6) is bonded in a 7-coordinate geometry to one O(11), one O(2), one O(3), one O(4), one O(5), one O(6), and one O(7) atom. There are three inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(12), one O(7), and one O(8) atom to form SiO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra and  a cornercorner with one Si(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-66°. In the second Si site, Si(2) is bonded in a tetrahedral geometry to one O(10), one O(11), one O(2), and one O(4) atom. In the third Si site, Si(3) is bonded to one O(13), one O(3), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ca(1)O6 octahedra and  a cornercorner with one Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-68°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one Ca(3), one Ca(5), and one O(6) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(9) atom. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(3), one Ca(4), one Ca(5), and one Si(1) atom. In the second O site, O(2) is bonded to one Ca(2), one Ca(4), one Ca(6), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the third O site, O(3) is bonded to one Ca(4), one Ca(5), one Ca(6), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the fourth O site, O(4) is bonded to one Ca(3), one Ca(4), one Ca(6), and one Si(2) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Ca(3), one Ca(6), and one Si(3) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ca(2), one Ca(3), one Ca(5), one Ca(6), and one H(1) atom. In the seventh O site, O(7) is bonded to one Ca(1), one Ca(4), one Ca(6), and one Si(1) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Ca(5), one Si(1), and one Si(3) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one Ca(1), one Ca(2), one Ca(3), one Ca(4), and one H(2) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Ca(3), two equivalent Ca(2), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a 4-coordinate geometry to one Ca(2), one Ca(3), one Ca(6), and one Si(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Ca(5), and one Si(1) atom. In the thirteenth O site, O(13) is bonded to one Ca(1), two equivalent Ca(5), and one Si(3) atom to form a mixture of distorted corner and edge-sharing OCa3Si trigonal pyramids. is represented by the CIF file [CIF]
data_Ca6Si3H2O13
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.893
_cell_length_b   7.006
_cell_length_c   12.985
_cell_angle_alpha   90.800
_cell_angle_beta   97.633
_cell_angle_gamma   98.053
_symmetry_Int_Tables_number   1
_cell_volume   615.038
_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  0.684  0.808  0.124  1.0
  Ca  Ca1  1  0.810  0.796  0.512  1.0
  Ca  Ca2  1  0.440  0.967  0.679  1.0
  Ca  Ca3  1  0.107  0.528  0.709  1.0
  Ca  Ca4  1  0.919  0.805  0.898  1.0
  Ca  Ca5  1  0.081  0.195  0.102  1.0
  Ca  Ca6  1  0.190  0.204  0.488  1.0
  Ca  Ca7  1  0.893  0.472  0.291  1.0
  Ca  Ca8  1  0.406  0.523  0.297  1.0
  Ca  Ca9  1  0.560  0.033  0.321  1.0
  Ca  Ca10  1  0.594  0.477  0.703  1.0
  Ca  Ca11  1  0.316  0.192  0.876  1.0
  Si  Si12  1  0.386  0.711  0.902  1.0
  Si  Si13  1  0.614  0.289  0.098  1.0
  Si  Si14  1  0.285  0.701  0.491  1.0
  Si  Si15  1  0.810  0.285  0.884  1.0
  Si  Si16  1  0.190  0.715  0.116  1.0
  Si  Si17  1  0.715  0.299  0.509  1.0
  H  H18  1  0.188  0.028  0.277  1.0
  H  H19  1  0.066  0.118  0.677  1.0
  H  H20  1  0.812  0.972  0.723  1.0
  H  H21  1  0.934  0.882  0.323  1.0
  O  O22  1  0.743  0.151  0.176  1.0
  O  O23  1  0.834  0.485  0.582  1.0
  O  O24  1  0.885  0.489  0.831  1.0
  O  O25  1  0.358  0.633  0.610  1.0
  O  O26  1  0.617  0.185  0.805  1.0
  O  O27  1  0.765  0.839  0.698  1.0
  O  O28  1  0.642  0.367  0.390  1.0
  O  O29  1  0.619  0.489  0.166  1.0
  O  O30  1  0.252  0.664  1.000  1.0
  O  O31  1  0.383  0.815  0.195  1.0
  O  O32  1  0.381  0.511  0.834  1.0
  O  O33  1  0.810  0.793  0.315  1.0
  O  O34  1  0.166  0.515  0.418  1.0
  O  O35  1  0.748  0.336  0.000  1.0
  O  O36  1  0.847  0.128  0.489  1.0
  O  O37  1  0.235  0.161  0.302  1.0
  O  O38  1  0.257  0.849  0.824  1.0
  O  O39  1  0.190  0.207  0.685  1.0
  O  O40  1  0.521  0.218  0.567  1.0
  O  O41  1  0.610  0.806  0.947  1.0
  O  O42  1  0.479  0.782  0.433  1.0
  O  O43  1  0.014  0.851  0.090  1.0
  O  O44  1  0.986  0.149  0.910  1.0
  O  O45  1  0.115  0.511  0.169  1.0
  O  O46  1  0.153  0.872  0.511  1.0
  O  O47  1  0.390  0.194  0.053  1.0
[/CIF]
.