Materials Data on Sr3Ir2O7 by Materials Project

Sr3Ir2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with four equivalent SrO12 cuboctahedra, faces with four equivalent SrO12 cuboctahedra, and faces with eight equivalent IrO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.64–3.07 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 2.47–2.91 Å. Ir4+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with five equivalent IrO6 octahedra and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–16°. There are a spread of Ir–O bond distances ranging from 2.00–2.04 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to five equivalent Sr2+ and one Ir4+ atom to form a mixture of distorted corner and edge-sharing OSr5Ir octahedra. The corner-sharing octahedra tilt angles range from 1–10°. In the second O2- site, O2- is bonded to four equivalent Sr2+ and two equivalent Ir4+ atoms to form distorted OSr4Ir2 octahedra that share corners with six OSr5Ir octahedra and edges with four equivalent OSr4Ir2 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the third O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+ and two equivalent Ir4+ atoms.