The material structure described by K4O9I2 crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent K sites. In the first K site, K(1) is bonded to six equivalent O(1) atoms to form KO6 octahedra that share corners with six equivalent I(1)O6 octahedra and faces with two equivalent K(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. In the second K site, K(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form distorted KO12 cuboctahedra that share corners with six equivalent K(2)O12 cuboctahedra, faces with two equivalent K(1)O6 octahedra, and faces with six equivalent I(1)O6 octahedra. In the third K site, K(3) is bonded in a distorted q6 geometry to three equivalent O(2) and six equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one K(1), one K(2), two equivalent K(3), and one I(1) atom. In the second O site, O(2) is bonded to two equivalent K(2), two equivalent K(3), and two equivalent I(1) atoms to form a mixture of distorted face and corner-sharing OK4I2 octahedra. The corner-sharing octahedral tilt angles range from 13-60°. I(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted IO6 octahedra that share corners with three equivalent K(1)O6 octahedra, faces with three equivalent K(2)O12 cuboctahedra, and  a faceface with one I(1)O6 octahedra. The corner-sharing octahedral tilt angles are 12°. is represented by the Crystallographic Information File (CIF) [CIF]
data_K4I2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.122
_cell_length_b   6.122
_cell_length_c   15.715
_cell_angle_alpha   89.999
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   510.131
_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  1.000  1.000  0.000  1.0
  K  K1  1  0.000  0.000  0.500  1.0
  K  K2  1  0.000  0.000  0.250  1.0
  K  K3  1  0.000  1.000  0.750  1.0
  K  K4  1  0.333  0.667  0.399  1.0
  K  K5  1  0.667  0.333  0.899  1.0
  K  K6  1  0.667  0.333  0.601  1.0
  K  K7  1  0.333  0.667  0.101  1.0
  I  I8  1  0.333  0.667  0.659  1.0
  I  I9  1  0.667  0.333  0.159  1.0
  I  I10  1  0.667  0.333  0.341  1.0
  I  I11  1  0.333  0.667  0.841  1.0
  O  O12  1  0.184  0.816  0.895  1.0
  O  O13  1  0.184  0.368  0.895  1.0
  O  O14  1  0.633  0.816  0.895  1.0
  O  O15  1  0.367  0.184  0.395  1.0
  O  O16  1  0.816  0.633  0.105  1.0
  O  O17  1  0.816  0.184  0.395  1.0
  O  O18  1  0.816  0.632  0.395  1.0
  O  O19  1  0.184  0.816  0.605  1.0
  O  O20  1  0.632  0.816  0.605  1.0
  O  O21  1  0.367  0.184  0.105  1.0
  O  O22  1  0.816  0.184  0.105  1.0
  O  O23  1  0.184  0.367  0.605  1.0
  O  O24  1  0.532  0.065  0.250  1.0
  O  O25  1  0.467  0.532  0.750  1.0
  O  O26  1  0.065  0.532  0.750  1.0
  O  O27  1  0.935  0.468  0.250  1.0
  O  O28  1  0.532  0.468  0.250  1.0
  O  O29  1  0.468  0.935  0.750  1.0
[/CIF]
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The material structure described by K4O9I2 crystallizes in the hexagonal P6_3/mmc space group. There are three inequivalent K sites. In the first K site, K(1) is bonded to six equivalent O(1) atoms to form KO6 octahedra that share corners with six equivalent I(1)O6 octahedra and faces with two equivalent K(2)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. In the second K site, K(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form distorted KO12 cuboctahedra that share corners with six equivalent K(2)O12 cuboctahedra, faces with two equivalent K(1)O6 octahedra, and faces with six equivalent I(1)O6 octahedra. In the third K site, K(3) is bonded in a distorted q6 geometry to three equivalent O(2) and six equivalent O(1) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one K(1), one K(2), two equivalent K(3), and one I(1) atom. In the second O site, O(2) is bonded to two equivalent K(2), two equivalent K(3), and two equivalent I(1) atoms to form a mixture of distorted face and corner-sharing OK4I2 octahedra. The corner-sharing octahedral tilt angles range from 13-60°. I(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted IO6 octahedra that share corners with three equivalent K(1)O6 octahedra, faces with three equivalent K(2)O12 cuboctahedra, and  a faceface with one I(1)O6 octahedra. The corner-sharing octahedral tilt angles are 12°. is represented by the Crystallographic Information File (CIF) [CIF]
data_K4I2O9
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.122
_cell_length_b   6.122
_cell_length_c   15.715
_cell_angle_alpha   89.999
_cell_angle_beta   90.000
_cell_angle_gamma   120.000
_symmetry_Int_Tables_number   1
_cell_volume   510.131
_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  1.000  1.000  0.000  1.0
  K  K1  1  0.000  0.000  0.500  1.0
  K  K2  1  0.000  0.000  0.250  1.0
  K  K3  1  0.000  1.000  0.750  1.0
  K  K4  1  0.333  0.667  0.399  1.0
  K  K5  1  0.667  0.333  0.899  1.0
  K  K6  1  0.667  0.333  0.601  1.0
  K  K7  1  0.333  0.667  0.101  1.0
  I  I8  1  0.333  0.667  0.659  1.0
  I  I9  1  0.667  0.333  0.159  1.0
  I  I10  1  0.667  0.333  0.341  1.0
  I  I11  1  0.333  0.667  0.841  1.0
  O  O12  1  0.184  0.816  0.895  1.0
  O  O13  1  0.184  0.368  0.895  1.0
  O  O14  1  0.633  0.816  0.895  1.0
  O  O15  1  0.367  0.184  0.395  1.0
  O  O16  1  0.816  0.633  0.105  1.0
  O  O17  1  0.816  0.184  0.395  1.0
  O  O18  1  0.816  0.632  0.395  1.0
  O  O19  1  0.184  0.816  0.605  1.0
  O  O20  1  0.632  0.816  0.605  1.0
  O  O21  1  0.367  0.184  0.105  1.0
  O  O22  1  0.816  0.184  0.105  1.0
  O  O23  1  0.184  0.367  0.605  1.0
  O  O24  1  0.532  0.065  0.250  1.0
  O  O25  1  0.467  0.532  0.750  1.0
  O  O26  1  0.065  0.532  0.750  1.0
  O  O27  1  0.935  0.468  0.250  1.0
  O  O28  1  0.532  0.468  0.250  1.0
  O  O29  1  0.468  0.935  0.750  1.0
[/CIF]
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