Materials Data on Ba2Ce3Si3O12F by Materials Project

Abstract

Ba2Ce3Si3O12F crystallizes in the hexagonal P6_3 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.68–3.05 Å. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.69–3.03 Å. Ce3+ is bonded to six O2- and one F1- atom to form CeO6F pentagonal bipyramids that share corners with six equivalent CeO6F pentagonal bipyramids, corners with four equivalent SiO4 tetrahedra, and an edgeedge with one SiO4 tetrahedra. There are a spread of Ce–O bond distances ranging from 2.33–2.56 Å. The Ce–F bond length is 2.51 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent CeO6F pentagonal bipyramids and an edgeedge with one CeO6F pentagonal bipyramid. There are a spread of Si–O bond distances ranging from 1.63–1.66 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Ba2+, two equivalent Ce3+, and one Si4+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Ba2+, two equivalent Ce3+, and one Si4+ atom. In the third O2- site, O2- is bonded to two Ba2+, one Ce3+, and one Si4+ atom to form distorted edge-sharing OBa2CeSi tetrahedra. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two Ba2+, one Ce3+, and one Si4+ atom. F1- is bonded in a trigonal planar geometry to three equivalent Ce3+ atoms.