Materials Data on CsK2Yb(PO4)2 by Materials Project
CsK2Yb(PO4)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Cs1+ is bonded to twelve O2- atoms to form CsO12 cuboctahedra that share edges with six equivalent CsO12 cuboctahedra, edges with six equivalent PO4 tetrahedra, and faces with two equivalent YbO6 octahedra. There are six shorter (3.21 Å) and six longer (3.40 Å) Cs–O bond lengths. K1+ is bonded in a 7-coordinate geometry to ten O2- atoms. There are a spread of K–O bond distances ranging from 2.79–3.30 Å. Yb3+ is bonded to six equivalent O2- atoms to form YbO6 octahedra that share corners with six equivalent PO4 tetrahedra and faces with two equivalent CsO12 cuboctahedra. All Yb–O bond lengths are 2.31 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent YbO6 octahedra and edges with three equivalent CsO12 cuboctahedra. The corner-sharing octahedral tilt angles are 15°. There is one shorter (1.55 Å) and three longer (1.56 Å) P–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Cs1+, one K1+, and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Cs1+, three equivalent K1+, one Yb3+, and one P5+ atom.