DOE OSTI2020
Ba4NaRu3O12 is (Cubic) Perovskite-derived structured and crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six RuO6 octahedra and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–5°. All Na–O bond lengths are 2.27 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 twelve BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, faces with three equivalent NaO6 octahedra, and faces with five RuO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.95–2.99 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with twelve BaO12 cuboctahedra, faces with six BaO12 cuboctahedra, a faceface with one NaO6 octahedra, and faces with seven RuO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.88–3.02 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 seven BaO12 cuboctahedra, faces with three equivalent NaO6 octahedra, and faces with four RuO6 octahedra. The corner-sharing octahedral tilt angles are 15°. There are a spread of Ba–O bond distances ranging from 2.95–3.17 Å. In the fourth 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 seven BaO12 cuboctahedra, a faceface with one NaO6 octahedra, and faces with six RuO6 octahedra. The corner-sharing octahedral tilt angles are 9°. There are a spread of Ba–O bond distances ranging from 2.93–2.95 Å. There are three inequivalent Ru5+ sites. In the first Ru5+ site, Ru5+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent RuO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedral tilt angles are 3°. There is three shorter (1.99 Å) and three longer (2.00 Å) Ru–O bond length. In the second Ru5+ site, Ru5+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent BaO12 cuboctahedra, corners with three equivalent NaO6 octahedra, faces with seven BaO12 cuboctahedra, and a faceface with one RuO6 octahedra. The corner-sharing octahedral tilt angles are 5°. There is three shorter (1.89 Å) and three longer (2.08 Å) Ru–O bond length. In the third Ru5+ site, Ru5+ is bonded to six O2- atoms to form RuO6 octahedra that share corners with three equivalent NaO6 octahedra, corners with three equivalent RuO6 octahedra, and faces with eight BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–3°. There is three shorter (1.89 Å) and three longer (2.08 Å) Ru–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one Na1+, four Ba2+, and one Ru5+ atom. In the second O2- site, O2- is bonded in a distorted linear geometry to four Ba2+ and two Ru5+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two Ru5+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to one Na1+, four Ba2+, and one Ru5+ atom.