Materials Data on Sr5Cr3O12F by Materials Project
Sr5Cr3O12F crystallizes in the hexagonal P6_3/m space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six O2- and one F1- atom to form distorted SrO6F pentagonal bipyramids that share corners with six equivalent SrO6F pentagonal bipyramids, corners with four equivalent CrO4 tetrahedra, and an edgeedge with one CrO4 tetrahedra. There are a spread of Sr–O bond distances ranging from 2.54–2.77 Å. The Sr–F bond length is 2.48 Å. In the second Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.60–2.99 Å. Cr5+ is bonded to four O2- atoms to form CrO4 tetrahedra that share corners with four equivalent SrO6F pentagonal bipyramids and an edgeedge with one SrO6F pentagonal bipyramid. There is two shorter (1.72 Å) and two longer (1.73 Å) Cr–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to three Sr2+ and one Cr5+ atom. In the second O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+ and one Cr5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to three Sr2+ and one Cr5+ atom. F1- is bonded in a trigonal planar geometry to three equivalent Sr2+ atoms.