The material described by K2Na2MgEu2Nb2O10 crystallizes in the tetragonal P4mm space group. K(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted single-bond geometry to one O(1) and four equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a distorted square co-planar geometry to four equivalent O(3) atoms. Mg(1) is bonded in a 4-coordinate geometry to four equivalent O(4) atoms. Eu(1) is bonded in a body-centered cubic geometry to four equivalent O(3) and four equivalent O(4) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a distorted trigonal bipyramidal geometry to one O(2) and four equivalent O(4) atoms. In the second Nb site, Nb(2) is bonded in a distorted trigonal bipyramidal geometry to one O(1) and four equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to four equivalent K(1), one Na(1), and one Nb(2) atom to form distorted OK4NaNb octahedra that share corners with four equivalent O(1)K4NaNb octahedra and corners with four equivalent O(3)NaEu2Nb tetrahedra. The corner-sharing octahedral tilt angles are 11°. In the second O site, O(2) is bonded in a distorted single-bond geometry to four equivalent K(1) and one Nb(1) atom. In the third O site, O(3) is bonded to one Na(2), two equivalent Eu(1), and one Nb(2) atom to form distorted ONaEu2Nb tetrahedra that share  a cornercorner with one O(1)K4NaNb octahedra, corners with four equivalent O(3)NaEu2Nb tetrahedra, and edges with four equivalent O(3)NaEu2Nb tetrahedra. The corner-sharing octahedral tilt angles are 74°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), one Mg(1), two equivalent Eu(1), and one Nb(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2Na2Eu2MgNb2O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.684
_cell_length_b   5.684
_cell_length_c   9.438
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   304.910
_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  0.250  0.750  0.970  1.0
  K  K1  1  0.750  0.250  0.970  1.0
  Na  Na2  1  0.750  0.750  0.160  1.0
  Na  Na3  1  0.250  0.250  0.746  1.0
  Eu  Eu4  1  0.750  0.250  0.526  1.0
  Eu  Eu5  1  0.250  0.750  0.526  1.0
  Mg  Mg6  1  0.750  0.750  0.401  1.0
  Nb  Nb7  1  0.250  0.250  0.287  1.0
  Nb  Nb8  1  0.750  0.750  0.737  1.0
  O  O9  1  0.750  0.750  0.940  1.0
  O  O10  1  0.250  0.250  0.088  1.0
  O  O11  1  0.985  0.985  0.678  1.0
  O  O12  1  0.515  0.515  0.678  1.0
  O  O13  1  0.494  0.494  0.346  1.0
  O  O14  1  0.985  0.515  0.678  1.0
  O  O15  1  0.515  0.985  0.678  1.0
  O  O16  1  0.006  0.494  0.346  1.0
  O  O17  1  0.006  0.006  0.346  1.0
  O  O18  1  0.494  0.006  0.346  1.0
[/CIF]
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The material described by K2Na2MgEu2Nb2O10 crystallizes in the tetragonal P4mm space group. K(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted single-bond geometry to one O(1) and four equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a distorted square co-planar geometry to four equivalent O(3) atoms. Mg(1) is bonded in a 4-coordinate geometry to four equivalent O(4) atoms. Eu(1) is bonded in a body-centered cubic geometry to four equivalent O(3) and four equivalent O(4) atoms. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a distorted trigonal bipyramidal geometry to one O(2) and four equivalent O(4) atoms. In the second Nb site, Nb(2) is bonded in a distorted trigonal bipyramidal geometry to one O(1) and four equivalent O(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to four equivalent K(1), one Na(1), and one Nb(2) atom to form distorted OK4NaNb octahedra that share corners with four equivalent O(1)K4NaNb octahedra and corners with four equivalent O(3)NaEu2Nb tetrahedra. The corner-sharing octahedral tilt angles are 11°. In the second O site, O(2) is bonded in a distorted single-bond geometry to four equivalent K(1) and one Nb(1) atom. In the third O site, O(3) is bonded to one Na(2), two equivalent Eu(1), and one Nb(2) atom to form distorted ONaEu2Nb tetrahedra that share  a cornercorner with one O(1)K4NaNb octahedra, corners with four equivalent O(3)NaEu2Nb tetrahedra, and edges with four equivalent O(3)NaEu2Nb tetrahedra. The corner-sharing octahedral tilt angles are 74°. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Na(1), one Mg(1), two equivalent Eu(1), and one Nb(1) atom. is represented by the Crystallographic Information File (CIF) [CIF]
data_K2Na2Eu2MgNb2O10
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.684
_cell_length_b   5.684
_cell_length_c   9.438
_cell_angle_alpha   90.000
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   304.910
_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  0.250  0.750  0.970  1.0
  K  K1  1  0.750  0.250  0.970  1.0
  Na  Na2  1  0.750  0.750  0.160  1.0
  Na  Na3  1  0.250  0.250  0.746  1.0
  Eu  Eu4  1  0.750  0.250  0.526  1.0
  Eu  Eu5  1  0.250  0.750  0.526  1.0
  Mg  Mg6  1  0.750  0.750  0.401  1.0
  Nb  Nb7  1  0.250  0.250  0.287  1.0
  Nb  Nb8  1  0.750  0.750  0.737  1.0
  O  O9  1  0.750  0.750  0.940  1.0
  O  O10  1  0.250  0.250  0.088  1.0
  O  O11  1  0.985  0.985  0.678  1.0
  O  O12  1  0.515  0.515  0.678  1.0
  O  O13  1  0.494  0.494  0.346  1.0
  O  O14  1  0.985  0.515  0.678  1.0
  O  O15  1  0.515  0.985  0.678  1.0
  O  O16  1  0.006  0.494  0.346  1.0
  O  O17  1  0.006  0.006  0.346  1.0
  O  O18  1  0.494  0.006  0.346  1.0
[/CIF]
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