K2SbPO6 crystallizes in the orthorhombic Pnma space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to one O(5), two equivalent O(1), two equivalent O(3), and three equivalent O(4) atoms to form distorted KO8 hexagonal bipyramids that share corners with four equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Sb(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, edges with two equivalent K(1)O8 hexagonal bipyramids, and edges with three equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-54°. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form SbO6 octahedra that share corners with four equivalent K(1)O8 hexagonal bipyramids, corners with two equivalent P(1)O4 tetrahedra, and edges with two equivalent Sb(1)O6 octahedra. P(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form PO4 tetrahedra that share  a cornercorner with one K(1)O8 hexagonal bipyramid, corners with two equivalent Sb(1)O6 octahedra, and edges with three equivalent K(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 54°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Sb(1), and one P(1) atom. In the second O site, O(2) is bonded to two equivalent K(2) and two equivalent Sb(1) atoms to form distorted corner-sharing OK2Sb2 tetrahedra. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1), two equivalent K(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(2), three equivalent K(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one K(1) and two equivalent Sb(1) atoms.
K2SbPO6 crystallizes in the orthorhombic Pnma space group. There are two inequivalent K sites. In the first K site, K(1) is bonded to one O(5), two equivalent O(1), two equivalent O(3), and three equivalent O(4) atoms to form distorted KO8 hexagonal bipyramids that share corners with four equivalent K(1)O8 hexagonal bipyramids, corners with four equivalent Sb(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, edges with two equivalent K(1)O8 hexagonal bipyramids, and edges with three equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-54°. The K(1)-O(5) bond length is 2.74 Å. Both K(1)-O(1) bond lengths are 2.80 Å. There is one shorter (2.76 Å) and one longer (3.02 Å) K(1)-O(3) bond length. There is one shorter (3.17 Å) and two longer (3.19 Å) K(1)-O(4) bond lengths. In the second K site, K(2) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The K(2)-O(4) bond length is 2.67 Å. Both K(2)-O(1) bond lengths are 3.21 Å. There is one shorter (2.90 Å) and one longer (2.95 Å) K(2)-O(2) bond length. Both K(2)-O(3) bond lengths are 3.05 Å. Sb(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms to form SbO6 octahedra that share corners with four equivalent K(1)O8 hexagonal bipyramids, corners with two equivalent P(1)O4 tetrahedra, and edges with two equivalent Sb(1)O6 octahedra. Both Sb(1)-O(1) bond lengths are 2.05 Å. Both Sb(1)-O(2) bond lengths are 2.02 Å. Both Sb(1)-O(5) bond lengths are 2.00 Å. P(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form PO4 tetrahedra that share  a cornercorner with one K(1)O8 hexagonal bipyramid, corners with two equivalent Sb(1)O6 octahedra, and edges with three equivalent K(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 54°. The P(1)-O(3) bond length is 1.52 Å. The P(1)-O(4) bond length is 1.52 Å. Both P(1)-O(1) bond lengths are 1.61 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one K(1), one K(2), one Sb(1), and one P(1) atom. In the second O site, O(2) is bonded to two equivalent K(2) and two equivalent Sb(1) atoms to form distorted corner-sharing OK2Sb2 tetrahedra. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent K(1), two equivalent K(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one K(2), three equivalent K(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one K(1) and two equivalent Sb(1) atoms.