The crystal structure described by K3MgNbO8 crystallizes in the orthorhombic I222 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to two equivalent O(1) and four equivalent O(2) atoms. In the second K site, K(2) is bonded in a distorted rectangular see-saw-like geometry to four equivalent O(1) atoms. Mg(1) is bonded in a square co-planar geometry to four equivalent O(1) and four equivalent O(2) atoms. Nb(1) is bonded in a distorted hexagonal bipyramidal geometry to four equivalent O(1) and four equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one K(2), one Mg(1), one Nb(1), and one O(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent K(1), one Mg(1), one Nb(1), and one O(1) atom. is represented by the CIF file [CIF]
data_K3MgNbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.982
_cell_length_b   6.982
_cell_length_c   6.982
_cell_angle_alpha   82.308
_cell_angle_beta   120.575
_cell_angle_gamma   128.696
_symmetry_Int_Tables_number   1
_cell_volume   219.973
_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  0.500  0.179  0.679  1.0
  K  K1  1  0.500  0.821  0.321  1.0
  K  K2  1  0.000  0.500  0.500  1.0
  Mg  Mg3  1  0.500  0.500  0.000  1.0
  Nb  Nb4  1  0.000  0.000  0.000  1.0
  O  O5  1  0.543  0.733  0.781  1.0
  O  O6  1  0.048  0.267  0.810  1.0
  O  O7  1  0.952  0.761  0.219  1.0
  O  O8  1  0.457  0.239  0.190  1.0
  O  O9  1  0.292  0.315  0.275  1.0
  O  O10  1  0.960  0.685  0.977  1.0
  O  O11  1  0.040  0.017  0.725  1.0
  O  O12  1  0.708  0.983  0.023  1.0
[/CIF]
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The crystal structure described by K3MgNbO8 crystallizes in the orthorhombic I222 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 6-coordinate geometry to two equivalent O(1) and four equivalent O(2) atoms. In the second K site, K(2) is bonded in a distorted rectangular see-saw-like geometry to four equivalent O(1) atoms. Mg(1) is bonded in a square co-planar geometry to four equivalent O(1) and four equivalent O(2) atoms. Nb(1) is bonded in a distorted hexagonal bipyramidal geometry to four equivalent O(1) and four equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one K(2), one Mg(1), one Nb(1), and one O(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent K(1), one Mg(1), one Nb(1), and one O(1) atom. is represented by the CIF file [CIF]
data_K3MgNbO8
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   6.982
_cell_length_b   6.982
_cell_length_c   6.982
_cell_angle_alpha   82.308
_cell_angle_beta   120.575
_cell_angle_gamma   128.696
_symmetry_Int_Tables_number   1
_cell_volume   219.973
_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  0.500  0.179  0.679  1.0
  K  K1  1  0.500  0.821  0.321  1.0
  K  K2  1  0.000  0.500  0.500  1.0
  Mg  Mg3  1  0.500  0.500  0.000  1.0
  Nb  Nb4  1  0.000  0.000  0.000  1.0
  O  O5  1  0.543  0.733  0.781  1.0
  O  O6  1  0.048  0.267  0.810  1.0
  O  O7  1  0.952  0.761  0.219  1.0
  O  O8  1  0.457  0.239  0.190  1.0
  O  O9  1  0.292  0.315  0.275  1.0
  O  O10  1  0.960  0.685  0.977  1.0
  O  O11  1  0.040  0.017  0.725  1.0
  O  O12  1  0.708  0.983  0.023  1.0
[/CIF]
.