DOE OSTI2020
Sr4CuIr2O9 is Orthorhombic Perovskite-derived structured and crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are twelve inequivalent Sr2+ sites. In the first 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 2.46–3.12 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. In the third Sr2+ site, Sr2+ is bonded in a 4-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.41–3.17 Å. In the fourth 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 2.45–2.89 Å. In the fifth 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 2.46–3.15 Å. In the sixth Sr2+ site, Sr2+ is bonded in a 9-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.42–2.93 Å. In the seventh Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.54–3.18 Å. In the eighth Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.52–3.19 Å. In the ninth Sr2+ site, Sr2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Sr–O bond distances ranging from 2.51–3.12 Å. In the tenth Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.44–2.90 Å. In the eleventh Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.50–2.84 Å. In the twelfth Sr2+ site, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Sr–O bond distances ranging from 2.47–2.79 Å. There are six inequivalent Ir+4.50+ sites. In the first Ir+4.50+ site, Ir+4.50+ is bonded to six O2- atoms to form face-sharing IrO6 octahedra. There are a spread of Ir–O bond distances ranging from 1.94–2.14 Å. In the second Ir+4.50+ site, Ir+4.50+ is bonded to six O2- atoms to form face-sharing IrO6 octahedra. There are a spread of Ir–O bond distances ranging from 1.94–2.15 Å. In the third Ir+4.50+ site, Ir+4.50+ is bonded to six O2- atoms to form face-sharing IrO6 octahedra. There are a spread of Ir–O bond distances ranging from 1.98–2.09 Å. In the fourth Ir+4.50+ site, Ir+4.50+ is bonded to six O2- atoms to form face-sharing IrO6 octahedra. There are a spread of Ir–O bond distances ranging from 1.98–2.10 Å. In the fifth Ir+4.50+ site, Ir+4.50+ is bonded to six O2- atoms to form face-sharing IrO6 octahedra. There are a spread of Ir–O bond distances ranging from 2.00–2.12 Å. In the sixth Ir+4.50+ site, Ir+4.50+ is bonded to six O2- atoms to form face-sharing IrO6 octahedra. There are a spread of Ir–O bond distances ranging from 1.99–2.13 Å. There are three inequivalent Cu1+ sites. In the first Cu1+ site, Cu1+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 2.04–2.06 Å. In the second Cu1+ site, Cu1+ is bonded in a distorted square co-planar geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 2.02–2.07 Å. In the third Cu1+ site, Cu1+ is bonded in a distorted square co-planar geometry to five O2- atoms. There are a spread of Cu–O bond distances ranging from 2.02–2.81 Å. There are twenty-seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the second O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the third O2- site, O2- is bonded in a 5-coordinate geometry to four Sr2+ and one Ir+4.50+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to four Sr2+ and one Ir+4.50+ atom. In the fifth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the sixth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the seventh O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+ and two Ir+4.50+ atoms. In the eighth O2- site, O2- is bonded to four Sr2+ and two Ir+4.50+ atoms to form distorted OSr4Ir2 octahedra that share corners with three OSr4CuIr octahedra, an edgeedge with one OSr4Ir2 octahedra, and faces with two OSr4CuIr octahedra. The corner-sharing octahedra tilt angles range from 45–65°. In the ninth O2- site, O2- is bonded to four Sr2+ and two Ir+4.50+ atoms to form distorted OSr4Ir2 octahedra that share corners with five OSr4Ir2 octahedra, an edgeedge with one OSr4CuIr octahedra, and faces with two OSr4CuIr octahedra. The corner-sharing octahedra tilt angles range from 31–58°. In the tenth O2- site, O2- is bonded to four Sr2+ and two Ir+4.50+ atoms to form distorted OSr4Ir2 octahedra that share corners with two OSr4CuIr octahedra, an edgeedge with one OSr4Ir2 octahedra, and faces with three OSr4Ir2 octahedra. The corner-sharing octahedra tilt angles range from 45–52°. In the eleventh O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+ and two Ir+4.50+ atoms. In the twelfth O2- site, O2- is bonded to four Sr2+ and two Ir+4.50+ atoms to form a mixture of distorted face, edge, and corner-sharing OSr4Ir2 octahedra. The corner-sharing octahedra tilt angles range from 2–59°. In the thirteenth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and one Ir+4.50+ atom. In the fourteenth O2- site, O2- is bonded in a 4-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the fifteenth O2- site, O2- is bonded in a 4-coordinate geometry to three Sr2+, one Ir+4.50+, and one Cu1+ atom. In the sixteenth O2- site, O2- is bonded in a 3-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the seventeenth O2- site, O2- is bonded in a 2-coordinate geometry to four Sr2+ and one Ir+4.50+ atom. In the eighteenth O2- site, O2- is bonded in a 4-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the nineteenth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the twentieth O2- site, O2- is bonded to four Sr2+, one Ir+4.50+, and one Cu1+ atom to form a mixture of distorted face, edge, and corner-sharing OSr4CuIr octahedra. The corner-sharing octahedra tilt angles range from 28–49°. In the twenty-first O2- site, O2- is bonded to four Sr2+, one Ir+4.50+, and one Cu1+ atom to form distorted OSr4CuIr octahedra that share corners with four OSr4Ir2 octahedra and faces with two OSr4CuIr octahedra. The corner-sharing octahedra tilt angles range from 2–65°. In the twenty-second O2- site, O2- is bonded to four Sr2+, one Ir+4.50+, and one Cu1+ atom to form distorted OSr4CuIr octahedra that share corners with four OSr4CuIr octahedra, an edgeedge with one OSr4Ir2 octahedra, and faces with three OSr4CuIr octahedra. The corner-sharing octahedra tilt angles range from 5–48°. In the twenty-third O2- site, O2- is bonded in a 5-coordinate geometry to four Sr2+ and one Ir+4.50+ atom. In the twenty-fourth O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+, one Ir+4.50+, and one Cu1+ atom. In the twenty-fifth O2- site, O2- is bonded to four Sr2+ and two Ir+4.50+ atoms to form a mixture of distorted face, edge, and corner-sharing OSr4Ir2 octahedra. The corner-sharing octahedra tilt angles range from 52–59°. In the twenty-sixth O2- site, O2- is bonded to four Sr2+ and two Ir+4.50+ atoms to form a mixture of distorted face, edge, and corner-sharing OSr4Ir2 octahedra. The corner-sharing octahedra tilt angles range from 27–59°. In the twenty-seventh O2- site, O2- is bonded in a 6-coordinate geometry to four Sr2+ and two Ir+4.50+ atoms.