DOE OSTI2020
Ba7Li3Ru4O20 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form distorted LiO4 trigonal pyramids that share corners with three equivalent RuO6 octahedra and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–5°. There are a spread of Li–O bond distances ranging from 1.90–2.08 Å. In the second Li1+ site, Li1+ is bonded to six O2- atoms to form LiO6 octahedra that share corners with six equivalent RuO6 octahedra and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 4–5°. All Li–O bond lengths are 2.15 Å. There are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, faces with three equivalent BaO12 cuboctahedra, a faceface with one LiO6 octahedra, faces with six RuO6 octahedra, and a faceface with one LiO4 trigonal pyramid. There are a spread of Ba–O bond distances ranging from 2.91–3.00 Å. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.83–3.18 Å. In the third Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, corners with three equivalent RuO6 octahedra, faces with six BaO12 cuboctahedra, faces with three equivalent LiO6 octahedra, and faces with four equivalent RuO6 octahedra. The corner-sharing octahedra tilt angles range from 8–9°. There are a spread of Ba–O bond distances ranging from 2.91–3.01 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.56–2.97 Å. There are two inequivalent Ru+5.75+ sites. In the first Ru+5.75+ site, Ru+5.75+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent LiO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedra tilt angles range from 4–5°. There are a spread of Ru–O bond distances ranging from 1.89–2.08 Å. In the second Ru+5.75+ site, Ru+5.75+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent LiO4 trigonal pyramids, faces with three equivalent BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. There are a spread of Ru–O bond distances ranging from 1.88–2.08 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded to four Ba2+ and two Ru+5.75+ atoms to form a mixture of distorted face and corner-sharing OBa4Ru2 octahedra. The corner-sharing octahedra tilt angles range from 6–60°. In the second O2- site, O2- is bonded to four Ba2+ and two Ru+5.75+ atoms to form a mixture of distorted face and corner-sharing OBa4Ru2 octahedra. The corner-sharing octahedra tilt angles range from 7–60°. In the third O2- site, O2- is bonded to four Ba2+ and two Ru+5.75+ atoms to form a mixture of distorted face and corner-sharing OBa4Ru2 octahedra. The corner-sharing octahedra tilt angles range from 7–60°. In the fourth O2- site, O2- is bonded in a distorted linear geometry to one Li1+, four Ba2+, and one Ru+5.75+ atom. In the fifth O2- site, O2- is bonded in a distorted linear geometry to one Li1+, four Ba2+, and one Ru+5.75+ atom. In the sixth O2- site, O2- is bonded in a distorted linear geometry to one Li1+, four Ba2+, and one Ru+5.75+ atom. In the seventh O2- site, O2- is bonded in a 1-coordinate geometry to one Li1+ and three Ba2+ atoms. In the eighth O2- site, O2- is bonded in a distorted linear geometry to one Li1+, four Ba2+, and one Ru+5.75+ atom. In the ninth O2- site, O2- is bonded in a distorted linear geometry to one Li1+, four Ba2+, and one Ru+5.75+ atom. In the tenth O2- site, O2- is bonded in a distorted linear geometry to one Li1+, four Ba2+, and one Ru+5.75+ atom.