Materials Data on CaBe2(PO4)2 by Materials Project

Abstract

CaBe2(PO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Ca2+ is bonded to seven O2- atoms to form distorted CaO7 hexagonal pyramids that share corners with five BeO4 tetrahedra, corners with five PO4 tetrahedra, an edgeedge with one BeO4 tetrahedra, and an edgeedge with one PO4 tetrahedra. There are a spread of Ca–O bond distances ranging from 2.43–2.61 Å. There are two inequivalent Be2+ sites. In the first Be2+ site, Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share corners with three equivalent CaO7 hexagonal pyramids and corners with four PO4 tetrahedra. There is one shorter (1.60 Å) and three longer (1.65 Å) Be–O bond length. In the second Be2+ site, Be2+ is bonded to four O2- atoms to form BeO4 tetrahedra that share corners with two equivalent CaO7 hexagonal pyramids, corners with four PO4 tetrahedra, and an edgeedge with one CaO7 hexagonal pyramid. There are a spread of Be–O bond distances ranging from 1.62–1.65 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent CaO7 hexagonal pyramids and corners with four BeO4 tetrahedra. There are a spread of P–O bond distances ranging from 1.52–1.56 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent CaO7 hexagonal pyramids, corners with four BeO4 tetrahedra, and an edgeedge with one CaO7 hexagonal pyramid. There is two shorter (1.54 Å) and two longer (1.56 Å) P–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Ca2+, one Be2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one Be2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one Be2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Ca2+, one Be2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Be2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Be2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Be2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Ca2+, one Be2+, and one P5+ atom.