The crystal structure described by K2Al2Si3(HO5)2 crystallizes in the orthorhombic Fdd2 space group. K(1) is bonded in a distorted rectangular see-saw-like geometry to one H(1), one O(2), one O(3), one O(4), and one O(5) atom. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. In the second Si site, Si(2) 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 Si(1)O4 tetrahedra and corners with three equivalent Al(1)O4 tetrahedra. H(1) is bonded in a single-bond geometry to one K(1) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one K(1), one Si(1), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2Al2Si3(HO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.132
_cell_length_b   10.520
_cell_length_c   10.498
_cell_angle_alpha   84.501
_cell_angle_beta   47.816
_cell_angle_gamma   47.684
_symmetry_Int_Tables_number   1
_cell_volume   649.708
_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
  K  K0  1  0.374  0.418  0.336  1.0
  K  K1  1  0.872  0.336  0.418  1.0
  K  K2  1  0.914  0.378  0.876  1.0
  K  K3  1  0.832  0.876  0.378  1.0
  Al  Al4  1  0.744  0.865  0.912  1.0
  Al  Al5  1  0.478  0.912  0.865  1.0
  Al  Al6  1  0.338  0.772  0.506  1.0
  Al  Al7  1  0.385  0.506  0.772  1.0
  Si  Si8  1  0.000  0.500  0.500  1.0
  Si  Si9  1  0.750  0.250  0.250  1.0
  Si  Si10  1  0.989  0.850  0.899  1.0
  Si  Si11  1  0.261  0.899  0.850  1.0
  Si  Si12  1  0.351  0.989  0.261  1.0
  Si  Si13  1  0.400  0.261  0.989  1.0
  H  H14  1  0.813  0.222  0.723  1.0
  H  H15  1  0.243  0.723  0.222  1.0
  H  H16  1  0.527  0.007  0.437  1.0
  H  H17  1  0.028  0.437  0.007  1.0
  O  O18  1  0.857  0.847  0.946  1.0
  O  O19  1  0.350  0.946  0.847  1.0
  O  O20  1  0.304  0.900  0.393  1.0
  O  O21  1  0.403  0.393  0.900  1.0
  O  O22  1  0.158  0.786  0.655  1.0
  O  O23  1  0.401  0.655  0.786  1.0
  O  O24  1  0.595  0.849  0.092  1.0
  O  O25  1  0.464  0.092  0.849  1.0
  O  O26  1  0.617  0.481  0.286  1.0
  O  O27  1  0.616  0.286  0.481  1.0
  O  O28  1  0.964  0.634  0.633  1.0
  O  O29  1  0.769  0.633  0.634  1.0
  O  O30  1  0.562  0.128  0.980  1.0
  O  O31  1  0.330  0.980  0.128  1.0
  O  O32  1  0.270  0.920  0.688  1.0
  O  O33  1  0.122  0.688  0.920  1.0
  O  O34  1  0.791  0.114  0.108  1.0
  O  O35  1  0.987  0.108  0.114  1.0
  O  O36  1  0.142  0.263  0.459  1.0
  O  O37  1  0.136  0.459  0.263  1.0
[/CIF]
.
The crystal structure described by K2Al2Si3(HO5)2 crystallizes in the orthorhombic Fdd2 space group. K(1) is bonded in a distorted rectangular see-saw-like geometry to one H(1), one O(2), one O(3), one O(4), and one O(5) atom. Al(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form AlO4 tetrahedra that share  a cornercorner with one Si(1)O4 tetrahedra and corners with three equivalent Si(2)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(3) and two equivalent O(5) atoms to form SiO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra and corners with two equivalent Si(2)O4 tetrahedra. In the second Si site, Si(2) 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 Si(1)O4 tetrahedra and corners with three equivalent Al(1)O4 tetrahedra. H(1) is bonded in a single-bond geometry to one K(1) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1) and one Si(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one Si(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one Si(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one K(1), one Al(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one K(1), one Si(1), and one Si(2) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2Al2Si3(HO5)2
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   14.132
_cell_length_b   10.520
_cell_length_c   10.498
_cell_angle_alpha   84.501
_cell_angle_beta   47.816
_cell_angle_gamma   47.684
_symmetry_Int_Tables_number   1
_cell_volume   649.708
_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
  K  K0  1  0.374  0.418  0.336  1.0
  K  K1  1  0.872  0.336  0.418  1.0
  K  K2  1  0.914  0.378  0.876  1.0
  K  K3  1  0.832  0.876  0.378  1.0
  Al  Al4  1  0.744  0.865  0.912  1.0
  Al  Al5  1  0.478  0.912  0.865  1.0
  Al  Al6  1  0.338  0.772  0.506  1.0
  Al  Al7  1  0.385  0.506  0.772  1.0
  Si  Si8  1  0.000  0.500  0.500  1.0
  Si  Si9  1  0.750  0.250  0.250  1.0
  Si  Si10  1  0.989  0.850  0.899  1.0
  Si  Si11  1  0.261  0.899  0.850  1.0
  Si  Si12  1  0.351  0.989  0.261  1.0
  Si  Si13  1  0.400  0.261  0.989  1.0
  H  H14  1  0.813  0.222  0.723  1.0
  H  H15  1  0.243  0.723  0.222  1.0
  H  H16  1  0.527  0.007  0.437  1.0
  H  H17  1  0.028  0.437  0.007  1.0
  O  O18  1  0.857  0.847  0.946  1.0
  O  O19  1  0.350  0.946  0.847  1.0
  O  O20  1  0.304  0.900  0.393  1.0
  O  O21  1  0.403  0.393  0.900  1.0
  O  O22  1  0.158  0.786  0.655  1.0
  O  O23  1  0.401  0.655  0.786  1.0
  O  O24  1  0.595  0.849  0.092  1.0
  O  O25  1  0.464  0.092  0.849  1.0
  O  O26  1  0.617  0.481  0.286  1.0
  O  O27  1  0.616  0.286  0.481  1.0
  O  O28  1  0.964  0.634  0.633  1.0
  O  O29  1  0.769  0.633  0.634  1.0
  O  O30  1  0.562  0.128  0.980  1.0
  O  O31  1  0.330  0.980  0.128  1.0
  O  O32  1  0.270  0.920  0.688  1.0
  O  O33  1  0.122  0.688  0.920  1.0
  O  O34  1  0.791  0.114  0.108  1.0
  O  O35  1  0.987  0.108  0.114  1.0
  O  O36  1  0.142  0.263  0.459  1.0
  O  O37  1  0.136  0.459  0.263  1.0
[/CIF]
.