The material described by K2Si4O9 crystallizes in the hexagonal P6_3/m space group. K(1) is bonded in a 9-coordinate geometry to three equivalent O(2) and six equivalent O(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(2)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. In the second Si site, Si(2) is bonded to six equivalent O(1) atoms to form corner-sharing SiO6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_K2Si4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.595
_cell_length_b   6.595
_cell_length_c   9.525
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   358.781
_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  0.333  0.667  0.443  1.0
  K  K1  1  0.667  0.333  0.943  1.0
  K  K2  1  0.667  0.333  0.557  1.0
  K  K3  1  0.333  0.667  0.057  1.0
  Si  Si4  1  0.635  0.766  0.750  1.0
  Si  Si5  1  0.869  0.635  0.250  1.0
  Si  Si6  1  0.766  0.131  0.250  1.0
  Si  Si7  1  0.234  0.869  0.750  1.0
  Si  Si8  1  0.131  0.365  0.750  1.0
  Si  Si9  1  0.365  0.234  0.250  1.0
  Si  Si10  1  0.000  0.000  0.500  1.0
  Si  Si11  1  0.000  0.000  0.000  1.0
  O  O12  1  0.232  0.210  0.394  1.0
  O  O13  1  0.021  0.232  0.894  1.0
  O  O14  1  0.210  0.979  0.894  1.0
  O  O15  1  0.790  0.021  0.394  1.0
  O  O16  1  0.979  0.768  0.394  1.0
  O  O17  1  0.768  0.790  0.894  1.0
  O  O18  1  0.768  0.790  0.606  1.0
  O  O19  1  0.979  0.768  0.106  1.0
  O  O20  1  0.790  0.021  0.106  1.0
  O  O21  1  0.210  0.979  0.606  1.0
  O  O22  1  0.021  0.232  0.606  1.0
  O  O23  1  0.232  0.210  0.106  1.0
  O  O24  1  0.491  0.073  0.250  1.0
  O  O25  1  0.418  0.491  0.750  1.0
  O  O26  1  0.073  0.582  0.750  1.0
  O  O27  1  0.927  0.418  0.250  1.0
  O  O28  1  0.582  0.509  0.250  1.0
  O  O29  1  0.509  0.927  0.750  1.0
[/CIF]
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The material described by K2Si4O9 crystallizes in the hexagonal P6_3/m space group. K(1) is bonded in a 9-coordinate geometry to three equivalent O(2) and six equivalent O(1) atoms. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form SiO4 tetrahedra that share corners with two equivalent Si(2)O6 octahedra and corners with two equivalent Si(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 38°. In the second Si site, Si(2) is bonded to six equivalent O(1) atoms to form corner-sharing SiO6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to two equivalent K(1), one Si(1), and one Si(2) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent K(1) and two equivalent Si(1) atoms. is represented by the CIF file [CIF]
data_K2Si4O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.595
_cell_length_b   6.595
_cell_length_c   9.525
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   358.781
_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  0.333  0.667  0.443  1.0
  K  K1  1  0.667  0.333  0.943  1.0
  K  K2  1  0.667  0.333  0.557  1.0
  K  K3  1  0.333  0.667  0.057  1.0
  Si  Si4  1  0.635  0.766  0.750  1.0
  Si  Si5  1  0.869  0.635  0.250  1.0
  Si  Si6  1  0.766  0.131  0.250  1.0
  Si  Si7  1  0.234  0.869  0.750  1.0
  Si  Si8  1  0.131  0.365  0.750  1.0
  Si  Si9  1  0.365  0.234  0.250  1.0
  Si  Si10  1  0.000  0.000  0.500  1.0
  Si  Si11  1  0.000  0.000  0.000  1.0
  O  O12  1  0.232  0.210  0.394  1.0
  O  O13  1  0.021  0.232  0.894  1.0
  O  O14  1  0.210  0.979  0.894  1.0
  O  O15  1  0.790  0.021  0.394  1.0
  O  O16  1  0.979  0.768  0.394  1.0
  O  O17  1  0.768  0.790  0.894  1.0
  O  O18  1  0.768  0.790  0.606  1.0
  O  O19  1  0.979  0.768  0.106  1.0
  O  O20  1  0.790  0.021  0.106  1.0
  O  O21  1  0.210  0.979  0.606  1.0
  O  O22  1  0.021  0.232  0.606  1.0
  O  O23  1  0.232  0.210  0.106  1.0
  O  O24  1  0.491  0.073  0.250  1.0
  O  O25  1  0.418  0.491  0.750  1.0
  O  O26  1  0.073  0.582  0.750  1.0
  O  O27  1  0.927  0.418  0.250  1.0
  O  O28  1  0.582  0.509  0.250  1.0
  O  O29  1  0.509  0.927  0.750  1.0
[/CIF]
.