The structure described by KNa2AlH6 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 10-coordinate geometry to one H(3), one H(5), two equivalent H(4), two equivalent H(6), and four equivalent H(1) atoms. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one H(4), one H(6), two equivalent H(2), two equivalent H(3), and two equivalent H(5) atoms. In the second Na site, Na(2) is bonded to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom to form NaH6 octahedra that share corners with six equivalent Al(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 14-27°. Al(1) is bonded to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom to form AlH6 octahedra that share corners with six equivalent Na(2)H6 octahedra. The corner-sharing octahedral tilt angles range from 14-27°. There are six inequivalent H sites. In the first H site, H(1) is bonded in a 4-coordinate geometry to four equivalent K(1), one Na(2), and one Al(1) atom. In the second H site, H(2) is bonded to one Na(2), two equivalent Na(1), and one Al(1) atom to form distorted corner-sharing HNa3Al tetrahedra. In the third H site, H(3) is bonded in a 5-coordinate geometry to one K(1), one Na(2), two equivalent Na(1), and one Al(1) atom. In the fourth H site, H(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Na(1), one Na(2), and one Al(1) atom. In the fifth H site, H(5) is bonded in a 3-coordinate geometry to one K(1), one Na(2), two equivalent Na(1), and one Al(1) atom. In the sixth H site, H(6) is bonded in a 5-coordinate geometry to two equivalent K(1), one Na(1), one Na(2), and one Al(1) atom. is represented by the CIF file [CIF]
data_KNa2AlH6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.663
_cell_length_b   5.584
_cell_length_c   7.988
_cell_angle_alpha   89.939
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   252.622
_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  0.981  0.241  0.500  1.0
  K  K1  1  0.481  0.759  0.500  1.0
  Na  Na2  1  0.039  0.250  1.000  1.0
  Na  Na3  1  0.539  0.750  0.000  1.0
  Na  Na4  1  0.502  0.253  0.759  1.0
  Na  Na5  1  0.002  0.747  0.241  1.0
  Al  Al6  1  0.499  0.240  0.233  1.0
  Al  Al7  1  0.999  0.760  0.767  1.0
  H  H8  1  0.510  0.290  0.457  1.0
  H  H9  1  0.010  0.710  0.543  1.0
  H  H10  1  0.471  0.170  0.021  1.0
  H  H11  1  0.971  0.830  0.979  1.0
  H  H12  1  0.818  0.502  0.798  1.0
  H  H13  1  0.318  0.498  0.202  1.0
  H  H14  1  0.187  0.009  0.740  1.0
  H  H15  1  0.687  0.991  0.260  1.0
  H  H16  1  0.753  0.422  0.200  1.0
  H  H17  1  0.253  0.578  0.800  1.0
  H  H18  1  0.249  0.059  0.269  1.0
  H  H19  1  0.749  0.941  0.731  1.0
[/CIF]
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The structure described by KNa2AlH6 is Orthorhombic Perovskite-derived structured and crystallizes in the monoclinic P2_1 space group. K(1) is bonded in a 10-coordinate geometry to one H(3), one H(5), two equivalent H(4), two equivalent H(6), and four equivalent H(1) atoms. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one H(4), one H(6), two equivalent H(2), two equivalent H(3), and two equivalent H(5) atoms. In the second Na site, Na(2) is bonded to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom to form NaH6 octahedra that share corners with six equivalent Al(1)H6 octahedra. The corner-sharing octahedral tilt angles range from 14-27°. Al(1) is bonded to one H(1), one H(2), one H(3), one H(4), one H(5), and one H(6) atom to form AlH6 octahedra that share corners with six equivalent Na(2)H6 octahedra. The corner-sharing octahedral tilt angles range from 14-27°. There are six inequivalent H sites. In the first H site, H(1) is bonded in a 4-coordinate geometry to four equivalent K(1), one Na(2), and one Al(1) atom. In the second H site, H(2) is bonded to one Na(2), two equivalent Na(1), and one Al(1) atom to form distorted corner-sharing HNa3Al tetrahedra. In the third H site, H(3) is bonded in a 5-coordinate geometry to one K(1), one Na(2), two equivalent Na(1), and one Al(1) atom. In the fourth H site, H(4) is bonded in a 5-coordinate geometry to two equivalent K(1), one Na(1), one Na(2), and one Al(1) atom. In the fifth H site, H(5) is bonded in a 3-coordinate geometry to one K(1), one Na(2), two equivalent Na(1), and one Al(1) atom. In the sixth H site, H(6) is bonded in a 5-coordinate geometry to two equivalent K(1), one Na(1), one Na(2), and one Al(1) atom. is represented by the CIF file [CIF]
data_KNa2AlH6
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   5.663
_cell_length_b   5.584
_cell_length_c   7.988
_cell_angle_alpha   89.939
_cell_angle_beta   90.000
_cell_angle_gamma   90.000
_symmetry_Int_Tables_number   1
_cell_volume   252.622
_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  0.981  0.241  0.500  1.0
  K  K1  1  0.481  0.759  0.500  1.0
  Na  Na2  1  0.039  0.250  1.000  1.0
  Na  Na3  1  0.539  0.750  0.000  1.0
  Na  Na4  1  0.502  0.253  0.759  1.0
  Na  Na5  1  0.002  0.747  0.241  1.0
  Al  Al6  1  0.499  0.240  0.233  1.0
  Al  Al7  1  0.999  0.760  0.767  1.0
  H  H8  1  0.510  0.290  0.457  1.0
  H  H9  1  0.010  0.710  0.543  1.0
  H  H10  1  0.471  0.170  0.021  1.0
  H  H11  1  0.971  0.830  0.979  1.0
  H  H12  1  0.818  0.502  0.798  1.0
  H  H13  1  0.318  0.498  0.202  1.0
  H  H14  1  0.187  0.009  0.740  1.0
  H  H15  1  0.687  0.991  0.260  1.0
  H  H16  1  0.753  0.422  0.200  1.0
  H  H17  1  0.253  0.578  0.800  1.0
  H  H18  1  0.249  0.059  0.269  1.0
  H  H19  1  0.749  0.941  0.731  1.0
[/CIF]
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