K2YSbO7 crystallizes in the orthorhombic Imma space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms to form KO8 hexagonal bipyramids that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with two equivalent Sb(1)O6 octahedra, edges with four equivalent K(2)O8 hexagonal bipyramids, edges with two equivalent Sb(1)O6 octahedra, and edges with four equivalent Y(1)O6 octahedra. The corner-sharing octahedral tilt angles are 50°. In the second K site, K(2) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted KO8 hexagonal bipyramids that share edges with two equivalent K(2)O8 hexagonal bipyramids, edges with four equivalent K(1)O8 hexagonal bipyramids, edges with two equivalent Y(1)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. Y(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form YO6 octahedra that share corners with two equivalent Y(1)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, edges with two equivalent K(2)O8 hexagonal bipyramids, and edges with four equivalent K(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 35-51°. Sb(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Y(1)O6 octahedra, edges with two equivalent K(1)O8 hexagonal bipyramids, and edges with four equivalent K(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 35°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one K(1), two equivalent K(2), and one Sb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Y(1), and one Sb(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Y(1) atoms.
K2YSbO7 crystallizes in the orthorhombic Imma space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to two equivalent O(1), two equivalent O(3), and four equivalent O(2) atoms to form KO8 hexagonal bipyramids that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with two equivalent Sb(1)O6 octahedra, edges with four equivalent K(2)O8 hexagonal bipyramids, edges with two equivalent Sb(1)O6 octahedra, and edges with four equivalent Y(1)O6 octahedra. The corner-sharing octahedral tilt angles are 50°. Both K(1)-O(1) bond lengths are 2.67 Å. Both K(1)-O(3) bond lengths are 3.07 Å. All K(1)-O(2) bond lengths are 2.97 Å. In the second K site, K(2) is bonded to four equivalent O(1) and four equivalent O(2) atoms to form distorted KO8 hexagonal bipyramids that share edges with two equivalent K(2)O8 hexagonal bipyramids, edges with four equivalent K(1)O8 hexagonal bipyramids, edges with two equivalent Y(1)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. All K(2)-O(1) bond lengths are 2.80 Å. All K(2)-O(2) bond lengths are 3.17 Å. Y(1) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form YO6 octahedra that share corners with two equivalent Y(1)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, edges with two equivalent K(2)O8 hexagonal bipyramids, and edges with four equivalent K(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 35-51°. Both Y(1)-O(3) bond lengths are 2.24 Å. All Y(1)-O(2) bond lengths are 2.28 Å. Sb(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Y(1)O6 octahedra, edges with two equivalent K(1)O8 hexagonal bipyramids, and edges with four equivalent K(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 35°. Both Sb(1)-O(1) bond lengths are 1.97 Å. All Sb(1)-O(2) bond lengths are 1.99 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one K(1), two equivalent K(2), and one Sb(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one K(1), one K(2), one Y(1), and one Sb(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent K(1) and two equivalent Y(1) atoms.