The crystal structure described by CaAl2Si4(HO7)2H2 crystallizes in the monoclinic C2/m space group. The structure consists of four 1333-74-0 molecules inside a CaAl2Si4(HO7)2 framework. In the CaAl2Si4(HO7)2 framework, Ca(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(8) atoms to form distorted CaO6 pentagonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(1)O4 tetrahedra. Al(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Ca(1)O6 pentagonal pyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 pentagonal pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 pentagonal pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. H(1) is bonded in a single-bond geometry to one O(8) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the second O site, O(8) is bonded in a distorted single-bond geometry to one Ca(1) and one H(1) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Al(1), and one Si(2) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the eighth O site, O(6) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF file [CIF]
data_CaAl2Si4(H2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.958
_cell_length_b   9.958
_cell_length_c   7.587
_cell_angle_alpha   75.127
_cell_angle_beta   75.127
_cell_angle_gamma   82.691
_symmetry_Int_Tables_number   1
_cell_volume   701.307
_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  0.758  0.758  0.267  1.0
  Ca  Ca1  1  0.242  0.242  0.733  1.0
  Al  Al2  1  0.436  0.817  0.260  1.0
  Al  Al3  1  0.183  0.564  0.740  1.0
  Al  Al4  1  0.564  0.183  0.740  1.0
  Al  Al5  1  0.817  0.436  0.260  1.0
  Si  Si6  1  0.623  0.858  0.844  1.0
  Si  Si7  1  0.142  0.377  0.156  1.0
  Si  Si8  1  0.377  0.142  0.156  1.0
  Si  Si9  1  0.858  0.623  0.844  1.0
  Si  Si10  1  0.464  0.698  0.673  1.0
  Si  Si11  1  0.302  0.536  0.327  1.0
  Si  Si12  1  0.536  0.302  0.327  1.0
  Si  Si13  1  0.698  0.464  0.673  1.0
  H  H14  1  0.726  0.095  0.277  1.0
  H  H15  1  0.905  0.274  0.723  1.0
  H  H16  1  0.274  0.905  0.723  1.0
  H  H17  1  0.095  0.726  0.277  1.0
  H  H18  1  0.953  0.011  0.321  1.0
  H  H19  1  0.989  0.047  0.679  1.0
  H  H20  1  0.047  0.989  0.679  1.0
  H  H21  1  0.011  0.953  0.321  1.0
  O  O22  1  0.762  0.762  0.769  1.0
  O  O23  1  0.238  0.238  0.231  1.0
  O  O24  1  0.589  0.825  0.074  1.0
  O  O25  1  0.175  0.411  0.926  1.0
  O  O26  1  0.411  0.175  0.926  1.0
  O  O27  1  0.825  0.589  0.074  1.0
  O  O28  1  0.524  0.753  0.446  1.0
  O  O29  1  0.247  0.476  0.554  1.0
  O  O30  1  0.476  0.247  0.554  1.0
  O  O31  1  0.753  0.524  0.446  1.0
  O  O32  1  0.491  0.810  0.784  1.0
  O  O33  1  0.190  0.509  0.216  1.0
  O  O34  1  0.509  0.190  0.216  1.0
  O  O35  1  0.810  0.491  0.784  1.0
  O  O36  1  0.352  0.981  0.251  1.0
  O  O37  1  0.019  0.648  0.749  1.0
  O  O38  1  0.648  0.019  0.749  1.0
  O  O39  1  0.981  0.352  0.251  1.0
  O  O40  1  0.548  0.548  0.743  1.0
  O  O41  1  0.452  0.452  0.257  1.0
  O  O42  1  0.298  0.687  0.725  1.0
  O  O43  1  0.313  0.702  0.275  1.0
  O  O44  1  0.702  0.313  0.275  1.0
  O  O45  1  0.687  0.298  0.725  1.0
  O  O46  1  0.726  0.993  0.300  1.0
  O  O47  1  0.007  0.274  0.700  1.0
  O  O48  1  0.274  0.007  0.700  1.0
  O  O49  1  0.993  0.726  0.300  1.0
[/CIF]
.
The crystal structure described by CaAl2Si4(HO7)2H2 crystallizes in the monoclinic C2/m space group. The structure consists of four 1333-74-0 molecules inside a CaAl2Si4(HO7)2 framework. In the CaAl2Si4(HO7)2 framework, Ca(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(8) atoms to form distorted CaO6 pentagonal pyramids that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and edges with two equivalent Al(1)O4 tetrahedra. Al(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form AlO4 tetrahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and  an edgeedge with one Ca(1)O6 pentagonal pyramid. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 pentagonal pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. In the second Si site, Si(2) is bonded to one O(3), one O(4), one O(6), and one O(7) atom to form SiO4 tetrahedra that share  a cornercorner with one Ca(1)O6 pentagonal pyramid,  a cornercorner with one Si(1)O4 tetrahedra,  a cornercorner with one Si(2)O4 tetrahedra, and corners with two equivalent Al(1)O4 tetrahedra. H(1) is bonded in a single-bond geometry to one O(8) atom. There are eight inequivalent O sites. In the first O site, O(7) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the second O site, O(8) is bonded in a distorted single-bond geometry to one Ca(1) and one H(1) atom. In the third O site, O(1) is bonded in a bent 150 degrees geometry to two equivalent Si(1) atoms. In the fourth O site, O(2) is bonded in a 3-coordinate geometry to one Ca(1), one Al(1), and one Si(1) atom. In the fifth O site, O(3) is bonded in a distorted trigonal planar geometry to one Ca(1), one Al(1), and one Si(2) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Si(1) and one Si(2) atom. In the seventh O site, O(5) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(1) atom. In the eighth O site, O(6) is bonded in a bent 150 degrees geometry to two equivalent Si(2) atoms. is represented by the CIF file [CIF]
data_CaAl2Si4(H2O7)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   9.958
_cell_length_b   9.958
_cell_length_c   7.587
_cell_angle_alpha   75.127
_cell_angle_beta   75.127
_cell_angle_gamma   82.691
_symmetry_Int_Tables_number   1
_cell_volume   701.307
_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  0.758  0.758  0.267  1.0
  Ca  Ca1  1  0.242  0.242  0.733  1.0
  Al  Al2  1  0.436  0.817  0.260  1.0
  Al  Al3  1  0.183  0.564  0.740  1.0
  Al  Al4  1  0.564  0.183  0.740  1.0
  Al  Al5  1  0.817  0.436  0.260  1.0
  Si  Si6  1  0.623  0.858  0.844  1.0
  Si  Si7  1  0.142  0.377  0.156  1.0
  Si  Si8  1  0.377  0.142  0.156  1.0
  Si  Si9  1  0.858  0.623  0.844  1.0
  Si  Si10  1  0.464  0.698  0.673  1.0
  Si  Si11  1  0.302  0.536  0.327  1.0
  Si  Si12  1  0.536  0.302  0.327  1.0
  Si  Si13  1  0.698  0.464  0.673  1.0
  H  H14  1  0.726  0.095  0.277  1.0
  H  H15  1  0.905  0.274  0.723  1.0
  H  H16  1  0.274  0.905  0.723  1.0
  H  H17  1  0.095  0.726  0.277  1.0
  H  H18  1  0.953  0.011  0.321  1.0
  H  H19  1  0.989  0.047  0.679  1.0
  H  H20  1  0.047  0.989  0.679  1.0
  H  H21  1  0.011  0.953  0.321  1.0
  O  O22  1  0.762  0.762  0.769  1.0
  O  O23  1  0.238  0.238  0.231  1.0
  O  O24  1  0.589  0.825  0.074  1.0
  O  O25  1  0.175  0.411  0.926  1.0
  O  O26  1  0.411  0.175  0.926  1.0
  O  O27  1  0.825  0.589  0.074  1.0
  O  O28  1  0.524  0.753  0.446  1.0
  O  O29  1  0.247  0.476  0.554  1.0
  O  O30  1  0.476  0.247  0.554  1.0
  O  O31  1  0.753  0.524  0.446  1.0
  O  O32  1  0.491  0.810  0.784  1.0
  O  O33  1  0.190  0.509  0.216  1.0
  O  O34  1  0.509  0.190  0.216  1.0
  O  O35  1  0.810  0.491  0.784  1.0
  O  O36  1  0.352  0.981  0.251  1.0
  O  O37  1  0.019  0.648  0.749  1.0
  O  O38  1  0.648  0.019  0.749  1.0
  O  O39  1  0.981  0.352  0.251  1.0
  O  O40  1  0.548  0.548  0.743  1.0
  O  O41  1  0.452  0.452  0.257  1.0
  O  O42  1  0.298  0.687  0.725  1.0
  O  O43  1  0.313  0.702  0.275  1.0
  O  O44  1  0.702  0.313  0.275  1.0
  O  O45  1  0.687  0.298  0.725  1.0
  O  O46  1  0.726  0.993  0.300  1.0
  O  O47  1  0.007  0.274  0.700  1.0
  O  O48  1  0.274  0.007  0.700  1.0
  O  O49  1  0.993  0.726  0.300  1.0
[/CIF]
.