The crystal structure described by K2HfO6 crystallizes in the orthorhombic Cmme space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(5), and four equivalent O(4) atoms. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Hf site, Hf(2) is bonded in an octahedral geometry to two equivalent O(5) and four equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(3) is bonded in a distorted T-shaped geometry to two equivalent K(1) and one Hf(1) atom. In the second O site, O(4) is bonded in a 1-coordinate geometry to one K(1), two equivalent K(2), and one Hf(2) atom. In the third O site, O(5) is bonded in a distorted T-shaped geometry to two equivalent K(2) and one Hf(2) atom. In the fourth O site, O(1) is bonded in a single-bond geometry to two equivalent K(1) and one Hf(1) atom. In the fifth O site, O(2) is bonded in a 5-coordinate geometry to two equivalent K(1), two equivalent K(2), and one Hf(1) atom. is represented by the CIF file [CIF]
data_K2HfO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.537
_cell_length_b   10.537
_cell_length_c   5.783
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   98.727
_symmetry_Int_Tables_number   1
_cell_volume   634.707
_cell_formula_units_Z   4
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  0.394  0.606  0.333  1.0
  K  K1  1  0.606  0.394  0.667  1.0
  K  K2  1  0.894  0.106  0.667  1.0
  K  K3  1  0.106  0.894  0.333  1.0
  K  K4  1  0.612  0.888  0.000  1.0
  K  K5  1  0.888  0.612  0.000  1.0
  K  K6  1  0.388  0.112  0.000  1.0
  K  K7  1  0.112  0.388  0.000  1.0
  Hf  Hf8  1  0.250  0.750  0.842  1.0
  Hf  Hf9  1  0.750  0.250  0.158  1.0
  Hf  Hf10  1  0.750  0.750  0.500  1.0
  Hf  Hf11  1  0.250  0.250  0.500  1.0
  O  O12  1  0.366  0.866  0.606  1.0
  O  O13  1  0.866  0.366  0.394  1.0
  O  O14  1  0.634  0.134  0.394  1.0
  O  O15  1  0.134  0.634  0.606  1.0
  O  O16  1  0.355  0.855  0.084  1.0
  O  O17  1  0.855  0.355  0.916  1.0
  O  O18  1  0.645  0.145  0.916  1.0
  O  O19  1  0.145  0.645  0.084  1.0
  O  O20  1  0.380  0.620  0.822  1.0
  O  O21  1  0.620  0.380  0.178  1.0
  O  O22  1  0.880  0.120  0.178  1.0
  O  O23  1  0.120  0.880  0.822  1.0
  O  O24  1  0.626  0.658  0.741  1.0
  O  O25  1  0.658  0.626  0.259  1.0
  O  O26  1  0.842  0.874  0.259  1.0
  O  O27  1  0.874  0.842  0.741  1.0
  O  O28  1  0.374  0.342  0.259  1.0
  O  O29  1  0.342  0.374  0.741  1.0
  O  O30  1  0.158  0.126  0.741  1.0
  O  O31  1  0.126  0.158  0.259  1.0
  O  O32  1  0.878  0.622  0.500  1.0
  O  O33  1  0.622  0.878  0.500  1.0
  O  O34  1  0.122  0.378  0.500  1.0
  O  O35  1  0.378  0.122  0.500  1.0
[/CIF]
.
The crystal structure described by K2HfO6 crystallizes in the orthorhombic Cmme space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(5), and four equivalent O(4) atoms. There are two inequivalent Hf sites. In the first Hf site, Hf(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Hf site, Hf(2) is bonded in an octahedral geometry to two equivalent O(5) and four equivalent O(4) atoms. There are five inequivalent O sites. In the first O site, O(3) is bonded in a distorted T-shaped geometry to two equivalent K(1) and one Hf(1) atom. In the second O site, O(4) is bonded in a 1-coordinate geometry to one K(1), two equivalent K(2), and one Hf(2) atom. In the third O site, O(5) is bonded in a distorted T-shaped geometry to two equivalent K(2) and one Hf(2) atom. In the fourth O site, O(1) is bonded in a single-bond geometry to two equivalent K(1) and one Hf(1) atom. In the fifth O site, O(2) is bonded in a 5-coordinate geometry to two equivalent K(1), two equivalent K(2), and one Hf(1) atom. is represented by the CIF file [CIF]
data_K2HfO6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   10.537
_cell_length_b   10.537
_cell_length_c   5.783
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   98.727
_symmetry_Int_Tables_number   1
_cell_volume   634.707
_cell_formula_units_Z   4
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  0.394  0.606  0.333  1.0
  K  K1  1  0.606  0.394  0.667  1.0
  K  K2  1  0.894  0.106  0.667  1.0
  K  K3  1  0.106  0.894  0.333  1.0
  K  K4  1  0.612  0.888  0.000  1.0
  K  K5  1  0.888  0.612  0.000  1.0
  K  K6  1  0.388  0.112  0.000  1.0
  K  K7  1  0.112  0.388  0.000  1.0
  Hf  Hf8  1  0.250  0.750  0.842  1.0
  Hf  Hf9  1  0.750  0.250  0.158  1.0
  Hf  Hf10  1  0.750  0.750  0.500  1.0
  Hf  Hf11  1  0.250  0.250  0.500  1.0
  O  O12  1  0.366  0.866  0.606  1.0
  O  O13  1  0.866  0.366  0.394  1.0
  O  O14  1  0.634  0.134  0.394  1.0
  O  O15  1  0.134  0.634  0.606  1.0
  O  O16  1  0.355  0.855  0.084  1.0
  O  O17  1  0.855  0.355  0.916  1.0
  O  O18  1  0.645  0.145  0.916  1.0
  O  O19  1  0.145  0.645  0.084  1.0
  O  O20  1  0.380  0.620  0.822  1.0
  O  O21  1  0.620  0.380  0.178  1.0
  O  O22  1  0.880  0.120  0.178  1.0
  O  O23  1  0.120  0.880  0.822  1.0
  O  O24  1  0.626  0.658  0.741  1.0
  O  O25  1  0.658  0.626  0.259  1.0
  O  O26  1  0.842  0.874  0.259  1.0
  O  O27  1  0.874  0.842  0.741  1.0
  O  O28  1  0.374  0.342  0.259  1.0
  O  O29  1  0.342  0.374  0.741  1.0
  O  O30  1  0.158  0.126  0.741  1.0
  O  O31  1  0.126  0.158  0.259  1.0
  O  O32  1  0.878  0.622  0.500  1.0
  O  O33  1  0.622  0.878  0.500  1.0
  O  O34  1  0.122  0.378  0.500  1.0
  O  O35  1  0.378  0.122  0.500  1.0
[/CIF]
.