The material described by K2Al2F9O2 crystallizes in the monoclinic P2_1/c space group. The structure consists of four water atoms inside a K2Al2F9 framework. In the K2Al2F9 framework, K(1) is bonded in a 6-coordinate geometry to two equivalent F(2), two equivalent F(3), and two equivalent F(4) atoms. Al(1) is bonded to one F(2), one F(3), one F(4), one F(5), and two equivalent F(1) atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. There are five inequivalent F sites. In the first F site, F(1) is bonded in a linear geometry to two equivalent Al(1) atoms. In the second F site, F(2) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Al(1) atom. In the third F site, F(3) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Al(1) atom. In the fourth F site, F(4) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Al(1) atom. In the fifth F site, F(5) is bonded in a linear geometry to two equivalent Al(1) atoms. is represented by the CIF card [CIF]
data_K2Al2O2F9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.014
_cell_length_b   3.780
_cell_length_c   11.196
_cell_angle_alpha   89.921
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   466.165
_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  0.817  1.000  0.855  1.0
  K  K1  1  0.183  0.000  0.145  1.0
  K  K2  1  0.683  1.000  0.355  1.0
  K  K3  1  0.317  0.000  0.645  1.0
  Al  Al4  1  0.607  0.499  0.631  1.0
  Al  Al5  1  0.393  0.501  0.369  1.0
  Al  Al6  1  0.893  0.499  0.131  1.0
  Al  Al7  1  0.107  0.501  0.869  1.0
  O  O8  1  0.935  0.389  0.569  1.0
  O  O9  1  0.435  0.611  0.931  1.0
  O  O10  1  0.065  0.611  0.431  1.0
  O  O11  1  0.565  0.389  0.069  1.0
  F  F12  1  0.600  1.000  0.621  1.0
  F  F13  1  0.400  0.000  0.379  1.0
  F  F14  1  0.900  1.000  0.121  1.0
  F  F15  1  0.100  0.000  0.879  1.0
  F  F16  1  0.703  0.500  0.754  1.0
  F  F17  1  0.297  0.500  0.246  1.0
  F  F18  1  0.797  0.500  0.254  1.0
  F  F19  1  0.203  0.500  0.746  1.0
  F  F20  1  0.472  0.499  0.726  1.0
  F  F21  1  0.528  0.501  0.274  1.0
  F  F22  1  0.028  0.499  0.226  1.0
  F  F23  1  0.972  0.501  0.774  1.0
  F  F24  1  0.732  0.501  0.524  1.0
  F  F25  1  0.268  0.499  0.476  1.0
  F  F26  1  0.768  0.501  0.024  1.0
  F  F27  1  0.232  0.499  0.976  1.0
  F  F28  1  0.500  0.500  0.500  1.0
  F  F29  1  0.000  0.500  0.000  1.0
[/CIF]
.
The material described by K2Al2F9O2 crystallizes in the monoclinic P2_1/c space group. The structure consists of four water atoms inside a K2Al2F9 framework. In the K2Al2F9 framework, K(1) is bonded in a 6-coordinate geometry to two equivalent F(2), two equivalent F(3), and two equivalent F(4) atoms. Al(1) is bonded to one F(2), one F(3), one F(4), one F(5), and two equivalent F(1) atoms to form corner-sharing AlF6 octahedra. The corner-sharing octahedral tilt angles range from 0-8°. There are five inequivalent F sites. In the first F site, F(1) is bonded in a linear geometry to two equivalent Al(1) atoms. In the second F site, F(2) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Al(1) atom. In the third F site, F(3) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Al(1) atom. In the fourth F site, F(4) is bonded in a distorted single-bond geometry to two equivalent K(1) and one Al(1) atom. In the fifth F site, F(5) is bonded in a linear geometry to two equivalent Al(1) atoms. is represented by the CIF card [CIF]
data_K2Al2O2F9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   11.014
_cell_length_b   3.780
_cell_length_c   11.196
_cell_angle_alpha   89.921
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   466.165
_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  0.817  1.000  0.855  1.0
  K  K1  1  0.183  0.000  0.145  1.0
  K  K2  1  0.683  1.000  0.355  1.0
  K  K3  1  0.317  0.000  0.645  1.0
  Al  Al4  1  0.607  0.499  0.631  1.0
  Al  Al5  1  0.393  0.501  0.369  1.0
  Al  Al6  1  0.893  0.499  0.131  1.0
  Al  Al7  1  0.107  0.501  0.869  1.0
  O  O8  1  0.935  0.389  0.569  1.0
  O  O9  1  0.435  0.611  0.931  1.0
  O  O10  1  0.065  0.611  0.431  1.0
  O  O11  1  0.565  0.389  0.069  1.0
  F  F12  1  0.600  1.000  0.621  1.0
  F  F13  1  0.400  0.000  0.379  1.0
  F  F14  1  0.900  1.000  0.121  1.0
  F  F15  1  0.100  0.000  0.879  1.0
  F  F16  1  0.703  0.500  0.754  1.0
  F  F17  1  0.297  0.500  0.246  1.0
  F  F18  1  0.797  0.500  0.254  1.0
  F  F19  1  0.203  0.500  0.746  1.0
  F  F20  1  0.472  0.499  0.726  1.0
  F  F21  1  0.528  0.501  0.274  1.0
  F  F22  1  0.028  0.499  0.226  1.0
  F  F23  1  0.972  0.501  0.774  1.0
  F  F24  1  0.732  0.501  0.524  1.0
  F  F25  1  0.268  0.499  0.476  1.0
  F  F26  1  0.768  0.501  0.024  1.0
  F  F27  1  0.232  0.499  0.976  1.0
  F  F28  1  0.500  0.500  0.500  1.0
  F  F29  1  0.000  0.500  0.000  1.0
[/CIF]
.