CsSb(PO4)2 crystallizes in the trigonal P-3 space group. Cs(1) is bonded to six equivalent O(1) atoms to form distorted CsO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with six equivalent Cs(1)O6 octahedra. Sb(1) is bonded to six equivalent O(2) atoms to form SbO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(1) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Cs(1)O6 octahedra and corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-63°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to three equivalent Cs(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Sb(1) and one P(1) atom.
CsSb(PO4)2 crystallizes in the trigonal P-3 space group. Cs(1) is bonded to six equivalent O(1) atoms to form distorted CsO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with six equivalent Cs(1)O6 octahedra. All Cs(1)-O(1) bond lengths are 3.18 Å. Sb(1) is bonded to six equivalent O(2) atoms to form SbO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra. All Sb(1)-O(2) bond lengths are 1.99 Å. P(1) is bonded to one O(1) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Cs(1)O6 octahedra and corners with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-63°. The P(1)-O(1) bond length is 1.49 Å. All P(1)-O(2) bond lengths are 1.58 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to three equivalent Cs(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Sb(1) and one P(1) atom.