The material described by CaAl4Si2O10(OH)2 crystallizes in the monoclinic Cc space group. Ca(1) is bonded to one O(10), one O(11), one O(12), one O(3), one O(4), and one O(5) atom to form CaO6 octahedra that share corners with three equivalent Al(1)O4 tetrahedra, corners with three equivalent Al(4)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and corners with three equivalent Si(2)O4 tetrahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(11), one O(3), one O(5), and one O(9) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and corners with three equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-64°. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(6), one O(7), one O(8), and one O(9) atom to form AlO6 octahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Al(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and edges with three equivalent Al(3)O6 octahedra. In the third Al site, Al(3) is bonded to one O(1), one O(2), one O(6), one O(7), one O(8), and one O(9) atom to form AlO6 octahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Al(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and edges with three equivalent Al(2)O6 octahedra. In the fourth Al site, Al(4) is bonded to one O(10), one O(12), one O(4), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and corners with three equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-64°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and corners with three equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-61°. In the second Si site, Si(2) is bonded to one O(10), one O(12), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and corners with three equivalent Al(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-61°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Al(2), one Al(3), and one H(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Al(2), one Al(3), and one H(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ca(1), one Al(4), and one Si(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Al(2), one Al(3), and one Al(4) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Al(2), one Al(3), and one Si(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Al(2), one Al(3), and one Si(2) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Al(1), one Al(2), and one Al(3) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Ca(1), one Al(4), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Ca(1), one Al(4), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaAl4Si2(HO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.157
_cell_length_b   5.157
_cell_length_c   19.414
_cell_angle_alpha   87.198
_cell_angle_beta   87.198
_cell_angle_gamma   120.041
_symmetry_Int_Tables_number   1
_cell_volume   444.771
_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  0.094  0.908  0.749  1.0
  Ca  Ca1  1  0.908  0.094  0.249  1.0
  Al  Al2  1  0.195  0.709  0.358  1.0
  Al  Al3  1  0.709  0.195  0.858  1.0
  Al  Al4  1  0.332  0.168  0.999  1.0
  Al  Al5  1  0.168  0.332  0.499  1.0
  Al  Al6  1  0.664  0.834  0.999  1.0
  Al  Al7  1  0.834  0.664  0.499  1.0
  Al  Al8  1  0.467  0.608  0.640  1.0
  Al  Al9  1  0.608  0.467  0.140  1.0
  Si  Si10  1  0.392  0.538  0.854  1.0
  Si  Si11  1  0.538  0.392  0.354  1.0
  Si  Si12  1  0.289  0.806  0.144  1.0
  Si  Si13  1  0.806  0.289  0.644  1.0
  H  H14  1  0.708  0.018  0.438  1.0
  H  H15  1  0.018  0.708  0.938  1.0
  H  H16  1  0.290  0.977  0.561  1.0
  H  H17  1  0.977  0.290  0.061  1.0
  O  O18  1  0.890  0.015  0.447  1.0
  O  O19  1  0.015  0.890  0.947  1.0
  O  O20  1  0.109  0.978  0.551  1.0
  O  O21  1  0.978  0.109  0.051  1.0
  O  O22  1  0.870  0.664  0.319  1.0
  O  O23  1  0.664  0.870  0.819  1.0
  O  O24  1  0.105  0.320  0.679  1.0
  O  O25  1  0.320  0.105  0.179  1.0
  O  O26  1  0.504  0.073  0.330  1.0
  O  O27  1  0.073  0.504  0.830  1.0
  O  O28  1  0.588  0.485  0.051  1.0
  O  O29  1  0.485  0.588  0.551  1.0
  O  O30  1  0.396  0.516  0.939  1.0
  O  O31  1  0.516  0.396  0.439  1.0
  O  O32  1  0.353  0.863  0.060  1.0
  O  O33  1  0.863  0.353  0.560  1.0
  O  O34  1  0.627  0.127  0.947  1.0
  O  O35  1  0.127  0.627  0.447  1.0
  O  O36  1  0.539  0.737  0.178  1.0
  O  O37  1  0.737  0.539  0.678  1.0
  O  O38  1  0.445  0.280  0.821  1.0
  O  O39  1  0.280  0.445  0.321  1.0
  O  O40  1  0.953  0.513  0.168  1.0
  O  O41  1  0.513  0.953  0.668  1.0
[/CIF]
.
The material described by CaAl4Si2O10(OH)2 crystallizes in the monoclinic Cc space group. Ca(1) is bonded to one O(10), one O(11), one O(12), one O(3), one O(4), and one O(5) atom to form CaO6 octahedra that share corners with three equivalent Al(1)O4 tetrahedra, corners with three equivalent Al(4)O4 tetrahedra, corners with three equivalent Si(1)O4 tetrahedra, and corners with three equivalent Si(2)O4 tetrahedra. There are four inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(11), one O(3), one O(5), and one O(9) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and corners with three equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 54-64°. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(6), one O(7), one O(8), and one O(9) atom to form AlO6 octahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Al(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and edges with three equivalent Al(3)O6 octahedra. In the third Al site, Al(3) is bonded to one O(1), one O(2), one O(6), one O(7), one O(8), and one O(9) atom to form AlO6 octahedra that share  a cornercorner with one Al(1)O4 tetrahedra,  a cornercorner with one Al(4)O4 tetrahedra,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and edges with three equivalent Al(2)O6 octahedra. In the fourth Al site, Al(4) is bonded to one O(10), one O(12), one O(4), and one O(6) atom to form AlO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and corners with three equivalent Si(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-64°. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(3), one O(5), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and corners with three equivalent Al(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-61°. In the second Si site, Si(2) is bonded to one O(10), one O(12), one O(4), and one O(8) atom to form SiO4 tetrahedra that share  a cornercorner with one Al(2)O6 octahedra,  a cornercorner with one Al(3)O6 octahedra, corners with three equivalent Ca(1)O6 octahedra, and corners with three equivalent Al(4)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 52-61°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Al(2), one Al(3), and one H(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Al(2), one Al(3), and one H(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Ca(1), one Al(4), and one Si(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Al(2), one Al(3), and one Al(4) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Al(2), one Al(3), and one Si(1) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to one Al(2), one Al(3), and one Si(2) atom. In the ninth O site, O(9) is bonded in a trigonal planar geometry to one Al(1), one Al(2), and one Al(3) atom. In the tenth O site, O(10) is bonded in a trigonal planar geometry to one Ca(1), one Al(4), and one Si(2) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one Ca(1), one Al(1), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Ca(1), one Al(4), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_CaAl4Si2(HO6)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.157
_cell_length_b   5.157
_cell_length_c   19.414
_cell_angle_alpha   87.198
_cell_angle_beta   87.198
_cell_angle_gamma   120.041
_symmetry_Int_Tables_number   1
_cell_volume   444.771
_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  0.094  0.908  0.749  1.0
  Ca  Ca1  1  0.908  0.094  0.249  1.0
  Al  Al2  1  0.195  0.709  0.358  1.0
  Al  Al3  1  0.709  0.195  0.858  1.0
  Al  Al4  1  0.332  0.168  0.999  1.0
  Al  Al5  1  0.168  0.332  0.499  1.0
  Al  Al6  1  0.664  0.834  0.999  1.0
  Al  Al7  1  0.834  0.664  0.499  1.0
  Al  Al8  1  0.467  0.608  0.640  1.0
  Al  Al9  1  0.608  0.467  0.140  1.0
  Si  Si10  1  0.392  0.538  0.854  1.0
  Si  Si11  1  0.538  0.392  0.354  1.0
  Si  Si12  1  0.289  0.806  0.144  1.0
  Si  Si13  1  0.806  0.289  0.644  1.0
  H  H14  1  0.708  0.018  0.438  1.0
  H  H15  1  0.018  0.708  0.938  1.0
  H  H16  1  0.290  0.977  0.561  1.0
  H  H17  1  0.977  0.290  0.061  1.0
  O  O18  1  0.890  0.015  0.447  1.0
  O  O19  1  0.015  0.890  0.947  1.0
  O  O20  1  0.109  0.978  0.551  1.0
  O  O21  1  0.978  0.109  0.051  1.0
  O  O22  1  0.870  0.664  0.319  1.0
  O  O23  1  0.664  0.870  0.819  1.0
  O  O24  1  0.105  0.320  0.679  1.0
  O  O25  1  0.320  0.105  0.179  1.0
  O  O26  1  0.504  0.073  0.330  1.0
  O  O27  1  0.073  0.504  0.830  1.0
  O  O28  1  0.588  0.485  0.051  1.0
  O  O29  1  0.485  0.588  0.551  1.0
  O  O30  1  0.396  0.516  0.939  1.0
  O  O31  1  0.516  0.396  0.439  1.0
  O  O32  1  0.353  0.863  0.060  1.0
  O  O33  1  0.863  0.353  0.560  1.0
  O  O34  1  0.627  0.127  0.947  1.0
  O  O35  1  0.127  0.627  0.447  1.0
  O  O36  1  0.539  0.737  0.178  1.0
  O  O37  1  0.737  0.539  0.678  1.0
  O  O38  1  0.445  0.280  0.821  1.0
  O  O39  1  0.280  0.445  0.321  1.0
  O  O40  1  0.953  0.513  0.168  1.0
  O  O41  1  0.513  0.953  0.668  1.0
[/CIF]
.