The crystal structure described by KCeNb4O12 crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent O(2), two equivalent O(3), four equivalent O(1), and four equivalent O(5) atoms to form distorted KO12 cuboctahedra that share corners with four equivalent K(1)O12 cuboctahedra and faces with eight equivalent Nb(1)O6 octahedra. Ce(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(1) atoms. Nb(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form NbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 11-21°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Ce(1), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one Ce(1), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one K(1) and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ce(1) and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Nb(1) atoms. is represented by the CIF card [CIF]
data_KCeNb4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.632
_cell_length_b   5.632
_cell_length_c   7.966
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.922
_symmetry_Int_Tables_number   1
_cell_volume   252.680
_cell_formula_units_Z   1
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  0.003  0.997  0.500  1.0
  Ce  Ce1  1  0.493  0.507  0.000  1.0
  Nb  Nb2  1  0.497  0.008  0.251  1.0
  Nb  Nb3  1  0.497  0.008  0.749  1.0
  Nb  Nb4  1  0.992  0.503  0.749  1.0
  Nb  Nb5  1  0.992  0.503  0.251  1.0
  O  O6  1  0.284  0.283  0.232  1.0
  O  O7  1  0.717  0.716  0.232  1.0
  O  O8  1  0.717  0.716  0.768  1.0
  O  O9  1  0.284  0.283  0.768  1.0
  O  O10  1  0.240  0.760  0.205  1.0
  O  O11  1  0.776  0.224  0.269  1.0
  O  O12  1  0.776  0.224  0.731  1.0
  O  O13  1  0.240  0.760  0.795  1.0
  O  O14  1  0.536  0.047  0.000  1.0
  O  O15  1  0.477  0.981  0.500  1.0
  O  O16  1  0.953  0.464  0.000  1.0
  O  O17  1  0.019  0.523  0.500  1.0
[/CIF]
.
The crystal structure described by KCeNb4O12 crystallizes in the orthorhombic Amm2 space group. K(1) is bonded to two equivalent O(2), two equivalent O(3), four equivalent O(1), and four equivalent O(5) atoms to form distorted KO12 cuboctahedra that share corners with four equivalent K(1)O12 cuboctahedra and faces with eight equivalent Nb(1)O6 octahedra. Ce(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), and four equivalent O(1) atoms. Nb(1) is bonded to one O(2), one O(3), one O(4), one O(5), and two equivalent O(1) atoms to form NbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra and faces with two equivalent K(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 11-21°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Ce(1), and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one Ce(1), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one K(1) and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ce(1) and two equivalent Nb(1) atoms. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Nb(1) atoms. is represented by the CIF card [CIF]
data_KCeNb4O12
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.632
_cell_length_b   5.632
_cell_length_c   7.966
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.922
_symmetry_Int_Tables_number   1
_cell_volume   252.680
_cell_formula_units_Z   1
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  0.003  0.997  0.500  1.0
  Ce  Ce1  1  0.493  0.507  0.000  1.0
  Nb  Nb2  1  0.497  0.008  0.251  1.0
  Nb  Nb3  1  0.497  0.008  0.749  1.0
  Nb  Nb4  1  0.992  0.503  0.749  1.0
  Nb  Nb5  1  0.992  0.503  0.251  1.0
  O  O6  1  0.284  0.283  0.232  1.0
  O  O7  1  0.717  0.716  0.232  1.0
  O  O8  1  0.717  0.716  0.768  1.0
  O  O9  1  0.284  0.283  0.768  1.0
  O  O10  1  0.240  0.760  0.205  1.0
  O  O11  1  0.776  0.224  0.269  1.0
  O  O12  1  0.776  0.224  0.731  1.0
  O  O13  1  0.240  0.760  0.795  1.0
  O  O14  1  0.536  0.047  0.000  1.0
  O  O15  1  0.477  0.981  0.500  1.0
  O  O16  1  0.953  0.464  0.000  1.0
  O  O17  1  0.019  0.523  0.500  1.0
[/CIF]
.