The material described by CaAl2Si(HO2)4 crystallizes in the tetragonal I4_1/a space group. Ca(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. Al(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra and edges with two equivalent Al(1)O6 octahedra. Si(1) is bonded to four equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. H(1) is bonded in a single-bond geometry to one O(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Ca(1), two equivalent Al(1), and one H(1) atom. is represented by the CIF file [CIF]
data_CaAl2Si(HO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.241
_cell_length_b   12.241
_cell_length_c   12.241
_cell_angle_alpha   156.391
_cell_angle_beta   156.391
_cell_angle_gamma   33.633
_symmetry_Int_Tables_number   1
_cell_volume   293.942
_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  0.250  0.750  0.500  1.0
  Ca  Ca1  1  0.500  0.500  0.000  1.0
  Al  Al2  1  0.410  0.910  0.500  1.0
  Al  Al3  1  0.660  0.660  0.000  1.0
  Al  Al4  1  0.340  0.340  0.000  1.0
  Al  Al5  1  0.090  0.590  0.500  1.0
  Si  Si6  1  0.750  0.250  0.500  1.0
  Si  Si7  1  0.000  0.000  0.000  1.0
  H  H8  1  0.789  0.219  0.190  1.0
  H  H9  1  0.029  0.600  0.810  1.0
  H  H10  1  0.350  0.039  0.070  1.0
  H  H11  1  0.969  0.279  0.930  1.0
  H  H12  1  0.961  0.031  0.310  1.0
  H  H13  1  0.721  0.650  0.690  1.0
  H  H14  1  0.400  0.211  0.430  1.0
  H  H15  1  0.781  0.971  0.570  1.0
  O  O16  1  0.844  0.967  0.388  1.0
  O  O17  1  0.580  0.456  0.612  1.0
  O  O18  1  0.206  0.094  0.376  1.0
  O  O19  1  0.717  0.830  0.624  1.0
  O  O20  1  0.906  0.283  0.112  1.0
  O  O21  1  0.170  0.794  0.888  1.0
  O  O22  1  0.544  0.156  0.124  1.0
  O  O23  1  0.033  0.420  0.876  1.0
  O  O24  1  0.592  0.233  0.015  1.0
  O  O25  1  0.218  0.578  0.985  1.0
  O  O26  1  0.328  0.842  0.859  1.0
  O  O27  1  0.983  0.468  0.141  1.0
  O  O28  1  0.158  0.017  0.485  1.0
  O  O29  1  0.532  0.672  0.515  1.0
  O  O30  1  0.422  0.408  0.641  1.0
  O  O31  1  0.767  0.782  0.359  1.0
[/CIF]
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The material described by CaAl2Si(HO2)4 crystallizes in the tetragonal I4_1/a space group. Ca(1) is bonded in a 8-coordinate geometry to four equivalent O(1) and four equivalent O(2) atoms. Al(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form AlO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra and edges with two equivalent Al(1)O6 octahedra. Si(1) is bonded to four equivalent O(1) atoms to form SiO4 tetrahedra that share corners with four equivalent Al(1)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. H(1) is bonded in a single-bond geometry to one O(2) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Ca(1), two equivalent Al(1), and one H(1) atom. is represented by the CIF file [CIF]
data_CaAl2Si(HO2)4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   12.241
_cell_length_b   12.241
_cell_length_c   12.241
_cell_angle_alpha   156.391
_cell_angle_beta   156.391
_cell_angle_gamma   33.633
_symmetry_Int_Tables_number   1
_cell_volume   293.942
_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  0.250  0.750  0.500  1.0
  Ca  Ca1  1  0.500  0.500  0.000  1.0
  Al  Al2  1  0.410  0.910  0.500  1.0
  Al  Al3  1  0.660  0.660  0.000  1.0
  Al  Al4  1  0.340  0.340  0.000  1.0
  Al  Al5  1  0.090  0.590  0.500  1.0
  Si  Si6  1  0.750  0.250  0.500  1.0
  Si  Si7  1  0.000  0.000  0.000  1.0
  H  H8  1  0.789  0.219  0.190  1.0
  H  H9  1  0.029  0.600  0.810  1.0
  H  H10  1  0.350  0.039  0.070  1.0
  H  H11  1  0.969  0.279  0.930  1.0
  H  H12  1  0.961  0.031  0.310  1.0
  H  H13  1  0.721  0.650  0.690  1.0
  H  H14  1  0.400  0.211  0.430  1.0
  H  H15  1  0.781  0.971  0.570  1.0
  O  O16  1  0.844  0.967  0.388  1.0
  O  O17  1  0.580  0.456  0.612  1.0
  O  O18  1  0.206  0.094  0.376  1.0
  O  O19  1  0.717  0.830  0.624  1.0
  O  O20  1  0.906  0.283  0.112  1.0
  O  O21  1  0.170  0.794  0.888  1.0
  O  O22  1  0.544  0.156  0.124  1.0
  O  O23  1  0.033  0.420  0.876  1.0
  O  O24  1  0.592  0.233  0.015  1.0
  O  O25  1  0.218  0.578  0.985  1.0
  O  O26  1  0.328  0.842  0.859  1.0
  O  O27  1  0.983  0.468  0.141  1.0
  O  O28  1  0.158  0.017  0.485  1.0
  O  O29  1  0.532  0.672  0.515  1.0
  O  O30  1  0.422  0.408  0.641  1.0
  O  O31  1  0.767  0.782  0.359  1.0
[/CIF]
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