Materials Data on Sr4Ca(FeO2)5 by Materials Project
Sr4Ca(FeO2)5 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.66 Å) and four longer (2.68 Å) Sr–O bond lengths. In the second Sr2+ site, Sr2+ is bonded in a body-centered cubic geometry to eight O2- atoms. All Sr–O bond lengths are 2.66 Å. Ca2+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Ca–O bond lengths are 2.62 Å. There are three inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are two shorter (2.02 Å) and two longer (2.04 Å) Fe–O bond lengths. In the second Fe2+ site, Fe2+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. All Fe–O bond lengths are 2.03 Å. In the third Fe2+ site, Fe2+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Fe–O bond lengths are 2.03 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to four Sr2+ and two Fe2+ atoms to form a mixture of edge, corner, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°. In the second O2- site, O2- is bonded to four equivalent Sr2+ and two equivalent Fe2+ atoms to form a mixture of edge, corner, and face-sharing OSr4Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°. In the third O2- site, O2- is bonded to two equivalent Sr2+, two equivalent Ca2+, and two Fe2+ atoms to form a mixture of distorted edge, corner, and face-sharing OSr2Ca2Fe2 octahedra. The corner-sharing octahedra tilt angles range from 0–66°.