Materials Data on Ba3Ti2(O3F5)2 by Materials Project

Abstract

Ba3Ti2(O3F5)2 crystallizes in the tetragonal P4_2/mbc space group. The structure is three-dimensional. there are two inequivalent Ba sites. In the first Ba site, Ba is bonded in a 10-coordinate geometry to six O and four F atoms. There are a spread of Ba–O bond distances ranging from 2.85–3.15 Å. There are a spread of Ba–F bond distances ranging from 2.63–2.77 Å. In the second Ba site, Ba is bonded to twelve F atoms to form distorted BaF12 cuboctahedra that share faces with two equivalent BaF12 cuboctahedra and faces with four equivalent TiO2F5 pentagonal bipyramids. There are a spread of Ba–F bond distances ranging from 2.75–3.05 Å. Ti is bonded to two equivalent O and five F atoms to form distorted TiO2F5 pentagonal bipyramids that share faces with two equivalent BaF12 cuboctahedra. Both Ti–O bond lengths are 1.99 Å. There are a spread of Ti–F bond distances ranging from 1.87–2.12 Å. There are two inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two equivalent Ba atoms. In the second O site, O is bonded in a 1-coordinate geometry to two equivalent Ba, one Ti, and one O atom. The O–O bond length is 1.43 Å. There are four inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to two equivalent Ba and one Ti atom. In the second F site, F is bonded in a distorted trigonal non-coplanar geometry to two Ba and one Ti atom. In the third F site, F is bonded to three Ba and one Ti atom to form a mixture of distorted edge and corner-sharing FBa3Ti tetrahedra. In the fourth F site, F is bonded in a distorted single-bond geometry to one Ba and one Ti atom.