Materials Data on Ba2B2O5 by Materials Project
Ba2B2O5 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to seven O2- atoms to form distorted BaO7 hexagonal pyramids that share edges with four equivalent BaO7 hexagonal pyramids and edges with two equivalent BaO6 pentagonal pyramids. There are a spread of Ba–O bond distances ranging from 2.68–2.92 Å. In the second Ba2+ site, Ba2+ is bonded to six O2- atoms to form distorted BaO6 pentagonal pyramids that share edges with two equivalent BaO7 hexagonal pyramids and edges with four equivalent BaO6 pentagonal pyramids. There are a spread of Ba–O bond distances ranging from 2.65–2.77 Å. There are two inequivalent B3+ sites. In the first B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.37 Å) and one longer (1.44 Å) B–O bond length. In the second B3+ site, B3+ is bonded in a trigonal planar geometry to three O2- atoms. There is two shorter (1.37 Å) and one longer (1.44 Å) B–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one B3+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one B3+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three Ba2+ and one B3+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to three equivalent Ba2+ and one B3+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Ba2+ and two B3+ atoms.