data_KY2O4
_symmetry_space_group_name_H-M   'P 1'
_cell_length_a   7.12
_cell_length_b   7.12
_cell_length_c   7.12
_cell_angle_alpha   60.0
_cell_angle_beta   60.0
_cell_angle_gamma   60.0
_symmetry_Int_Tables_number   1
_chemical_formula_structural   KY2O4
_chemical_formula_sum   'K2 Y4 O8'
_cell_volume   254.74
_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  0.0  0.0  0.0  1.0
  K  K1  1  0.52  0.52  0.52  1.0
  Y  Y10  1  0.77  0.77  0.29  1.0
  Y  Y11  1  0.77  0.29  0.77  1.0
  Y  Y12  1  0.29  0.77  0.77  1.0
  Y  Y13  1  0.29  0.29  0.29  1.0
  O  O2  1  0.01  0.01  0.01  1.0
  O  O3  1  0.01  0.05  0.05  1.0
  O  O4  1  0.05  0.01  0.05  1.0
  O  O5  1  0.52  0.52  0.57  1.0
  O  O6  1  0.05  0.05  0.01  1.0
  O  O7  1  0.52  0.57  0.52  1.0
  O  O8  1  0.57  0.57  0.57  1.0
  O  O9  1  0.57  0.52  0.52  1.0

data_KY2O4
_symmetry_space_group_name_H-M   R3m
_cell_length_a   7.12
_cell_length_b   7.12
_cell_length_c   17.43
_cell_angle_alpha   90.0
_cell_angle_beta   90.0
_cell_angle_gamma   120.0
_symmetry_Int_Tables_number   160
_chemical_formula_structural   KY2O4
_chemical_formula_sum   'K6 Y12 O24'
_cell_volume   764.21
_cell_formula_units_Z   6
loop_
 _symmetry_equiv_pos_site_id
 _symmetry_equiv_pos_as_xyz
  1  'x, y, z'
  2  '-y, x-y, z'
  3  '-x+y, -x, z'
  4  '-y, -x, z'
  5  '-x+y, y, z'
  6  'x, x-y, z'
  7  'x+1/3, y+2/3, z+2/3'
  8  '-y+1/3, x-y+2/3, z+2/3'
  9  '-x+y+1/3, -x+2/3, z+2/3'
  10  '-y+1/3, -x+2/3, z+2/3'
  11  '-x+y+1/3, y+2/3, z+2/3'
  12  'x+1/3, x-y+2/3, z+2/3'
  13  'x+2/3, y+1/3, z+1/3'
  14  '-y+2/3, x-y+1/3, z+1/3'
  15  '-x+y+2/3, -x+1/3, z+1/3'
  16  '-y+2/3, -x+1/3, z+1/3'
  17  '-x+y+2/3, y+1/3, z+1/3'
  18  'x+2/3, x-y+1/3, z+1/3'
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  3  0.0  0.0  0.0  1.0
  K  K1  3  0.0  0.0  0.48  1.0
  Y  Y2  9  0.17  0.34  0.05  1.0
  Y  Y3  3  0.0  0.0  0.71  1.0
  O  O4  9  0.02  0.03  0.46  1.0
  O  O5  9  0.03  0.02  0.96  1.0
  O  O6  3  0.0  0.0  0.43  1.0
  O  O7  3  0.0  0.0  0.99  1.0

K K Y Y Y Y O O O O O O O O
K K Y Y Y Y O O O O O O O O 0 6 o o o 0 2 - - o 0 3 - o - 0 4 o - - 0 5 o o - 0 5 o - o 0 5 - o o 1 13 o o o 1 11 o o o 1 9 o o o 1 2 o o o 1 3 o o o 1 4 o o o 1 5 o + o 1 5 + o o 1 5 o o + 1 5 o o o 2 13 o o o 2 12 o o o 2 11 o o o 2 9 o o o 2 6 + + o 2 8 + + o 2 7 + + o 2 5 + o o 2 5 o + o 3 13 o o o 3 12 o o o 3 11 o o o 3 9 o o o 3 10 + o + 3 7 + o + 3 6 + o + 3 5 + o o 3 5 o o + 4 10 o + + 4 8 o + + 4 6 o + + 4 13 o o o 4 12 o o o 4 11 o o o 4 9 o o o 4 5 o + o 4 5 o o + 5 10 o o o 5 10 o o + 5 10 + o o 5 10 o + o 5 8 o o o 5 8 o o + 5 8 + o o 5 8 o + o 5 7 o o o 5 7 o o + 5 7 o + o 5 7 + o o 5 11 o - o 5 11 - o o 5 11 o o - 5 11 o o o 5 6 o o + 5 6 o + o 5 6 + o o 5 9 o - o 5 9 - o o 5 9 o o - 5 9 o o o 5 13 - o o 5 13 o - o 5 13 o o - 5 13 o o o 5 12 - o o 5 12 o - o 5 12 o o - 7 8 o o o 7 10 o o o 8 10 o o o 9 13 o o o 9 11 o o o 9 12 o o o 11 13 o o o 11 12 o o o 12 13 o o o 
KY2O4 crystallizes in the trigonal R3m space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a single-bond geometry to three equivalent Y(1) and one O(1) atom. All K(1)-Y(1) bond lengths are 2.32 Å. The K(1)-O(1) bond length is 0.15 Å. In the second K site, K(2) is bonded in a 3-coordinate geometry to one Y(2) and three equivalent O(3) atoms. The K(2)-Y(2) bond length is 3.95 Å. All K(2)-O(3) bond lengths are 0.45 Å. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a 2-coordinate geometry to one K(1), two equivalent Y(2), and one O(4) atom. Both Y(1)-Y(2) bond lengths are 3.56 Å. The Y(1)-O(4) bond length is 2.12 Å. In the second Y site, Y(2) is bonded to one K(2) and six equivalent Y(1) atoms to form distorted corner-sharing YKY6 hexagonal pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one K(1) and three equivalent O(2) atoms. All O(1)-O(2) bond lengths are 0.56 Å. In the second O site, O(2) is bonded in a 3-coordinate geometry to one O(1) and two equivalent O(2) atoms. Both O(2)-O(2) bond lengths are 0.33 Å. In the third O site, O(3) is bonded in a 2-coordinate geometry to one K(2), one O(4), and two equivalent O(3) atoms. The O(3)-O(4) bond length is 0.56 Å. Both O(3)-O(3) bond lengths are 0.33 Å. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to three equivalent Y(1) and three equivalent O(3) atoms.