Materials Data on Ba2Y3Si2O8F5 by Materials Project

Ba2Y3(SiO4)2F5 crystallizes in the orthorhombic Pba2 space group. The structure is three-dimensional. Ba2+ is bonded in a 9-coordinate geometry to six O2- and three F1- atoms. There are a spread of Ba–O bond distances ranging from 2.71–3.06 Å. There are a spread of Ba–F bond distances ranging from 2.60–3.09 Å. There are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded in a 8-coordinate geometry to six O2- and two equivalent F1- atoms. There are a spread of Y–O bond distances ranging from 2.35–2.41 Å. Both Y–F bond lengths are 2.43 Å. In the second Y3+ site, Y3+ is bonded to three O2- and four F1- atoms to form distorted YO3F4 pentagonal bipyramids that share corners with three equivalent SiO4 tetrahedra and a faceface with one YO3F4 pentagonal bipyramid. There are a spread of Y–O bond distances ranging from 2.25–2.35 Å. There are a spread of Y–F bond distances ranging from 2.23–2.35 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with three equivalent YO3F4 pentagonal bipyramids. There are a spread of Si–O bond distances ranging from 1.63–1.67 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two equivalent Ba2+, one Y3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, two Y3+, and one Si4+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, two Y3+, and one Si4+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ba2+, one Y3+, and one Si4+ atom. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 3-coordinate geometry to one Ba2+ and two equivalent Y3+ atoms. In the second F1- site, F1- is bonded in a 2-coordinate geometry to one Ba2+ and two Y3+ atoms. In the third F1- site, F1- is bonded in a distorted water-like geometry to two equivalent Ba2+ and two equivalent Y3+ atoms.