Materials Data on BaHf(PO4)2 by Materials Project
BaHf(PO4)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.86–3.18 Å. Hf4+ is bonded to six O2- atoms to form HfO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are two shorter (2.02 Å) and four longer (2.09 Å) Hf–O bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent HfO6 octahedra. The corner-sharing octahedra tilt angles range from 22–39°. There are a spread of P–O bond distances ranging from 1.52–1.56 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+, one Hf4+, and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Hf4+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one P5+ atom.