Materials Data on K3PSe16 by Materials Project
K3PSe16 crystallizes in the cubic Fd-3 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to twelve equivalent Se+0.50- atoms to form corner-sharing KSe12 cuboctahedra. All K–Se bond lengths are 3.82 Å. In the second K1+ site, K1+ is bonded to twelve Se+0.50- atoms to form KSe12 cuboctahedra that share corners with six equivalent KSe12 cuboctahedra, edges with six equivalent KSe12 cuboctahedra, and faces with two equivalent PSe4 tetrahedra. There are six shorter (3.58 Å) and six longer (3.80 Å) K–Se bond lengths. P5+ is bonded to four equivalent Se+0.50- atoms to form PSe4 tetrahedra that share faces with four equivalent KSe12 cuboctahedra. All P–Se bond lengths are 2.24 Å. There are two inequivalent Se+0.50- sites. In the first Se+0.50- site, Se+0.50- is bonded in a 4-coordinate geometry to two K1+ and two equivalent Se+0.50- atoms. Both Se–Se bond lengths are 2.41 Å. In the second Se+0.50- site, Se+0.50- is bonded in a distorted single-bond geometry to three equivalent K1+ and one P5+ atom.