Materials Data on K2Ce(PO4)2 by Materials Project
K2Ce(PO4)2 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional. K1+ is bonded to four equivalent O2- atoms to form distorted KO4 hexagonal bipyramids that share corners with four equivalent PO4 tetrahedra and edges with two equivalent KO4 hexagonal bipyramids. All K–O bond lengths are 2.82 Å. Ce4+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.26 Å) and four longer (2.56 Å) Ce–O bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent KO4 hexagonal bipyramids. All P–O bond lengths are 1.55 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ce4+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+, one Ce4+, and one P5+ atom.