Materials Data on Ca10P6SeO24 by Materials Project

Abstract

Ca10(PO4)6Se crystallizes in the trigonal P-3 space group. The structure is three-dimensional. there are three inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 7-coordinate geometry to one Se2- and six O2- atoms. The Ca–Se bond length is 3.01 Å. There are a spread of Ca–O bond distances ranging from 2.35–2.86 Å. In the second Ca2+ site, Ca2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ca–O bond distances ranging from 2.47–2.72 Å. In the third Ca2+ site, Ca2+ is bonded to six O2- atoms to form distorted CaO6 pentagonal pyramids that share corners with six equivalent PO4 tetrahedra. There are three shorter (2.36 Å) and three longer (2.37 Å) Ca–O bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CaO6 pentagonal pyramids. There is two shorter (1.55 Å) and two longer (1.56 Å) P–O bond length. Se2- is bonded in a distorted octahedral geometry to six equivalent Ca2+ atoms. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Ca2+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ca2+ and one P5+ atom.