DOE OSTI2020
Ba4Sr2La2Co4O15 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eight inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form distorted BaO12 cuboctahedra that share faces with two equivalent CoO6 octahedra and faces with three CoO4 tetrahedra. There are a spread of Ba–O bond distances ranging from 2.77–3.25 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share faces with two equivalent CoO6 octahedra and faces with three CoO4 tetrahedra. There are a spread of Ba–O bond distances ranging from 2.77–3.24 Å. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–3.07 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 2.79–3.37 Å. In the fifth 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 2.76–3.43 Å. In the sixth 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 2.79–3.37 Å. In the seventh Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Ba–O bond distances ranging from 2.77–3.07 Å. In the eighth 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 2.76–3.41 Å. There are four inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with six CoO4 tetrahedra and faces with two equivalent SrO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.49–2.62 Å. In the second Sr2+ site, Sr2+ is bonded to six O2- atoms to form SrO6 octahedra that share corners with six CoO4 tetrahedra and faces with two equivalent SrO6 octahedra. There are a spread of Sr–O bond distances ranging from 2.49–2.62 Å. In the third 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 2.49–2.73 Å. In the fourth 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 2.49–2.73 Å. There are four inequivalent La3+ sites. In the first La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.38–2.68 Å. In the second La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.40–2.68 Å. In the third La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.38–2.69 Å. In the fourth La3+ site, La3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of La–O bond distances ranging from 2.40–2.68 Å. There are eight inequivalent Co3+ sites. In the first Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share a cornercorner with one CoO6 octahedra, corners with two SrO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–63°. There are a spread of Co–O bond distances ranging from 1.81–1.94 Å. In the second Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share a cornercorner with one CoO6 octahedra, corners with two SrO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 4–64°. There are a spread of Co–O bond distances ranging from 1.82–1.94 Å. In the third Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share a cornercorner with one CoO6 octahedra, corners with two SrO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–63°. There are a spread of Co–O bond distances ranging from 1.83–1.92 Å. In the fourth Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share a cornercorner with one CoO6 octahedra, corners with two SrO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 4–64°. There are a spread of Co–O bond distances ranging from 1.82–1.94 Å. In the fifth Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share a cornercorner with one CoO6 octahedra, corners with two SrO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–63°. There are a spread of Co–O bond distances ranging from 1.81–1.94 Å. In the sixth Co3+ site, Co3+ is bonded to four O2- atoms to form CoO4 tetrahedra that share a cornercorner with one CoO6 octahedra, corners with two SrO6 octahedra, and a faceface with one BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–64°. There is two shorter (1.83 Å) and two longer (1.92 Å) Co–O bond length. In the seventh Co3+ site, Co3+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with three CoO4 tetrahedra and faces with two equivalent BaO12 cuboctahedra. There are a spread of Co–O bond distances ranging from 1.86–2.26 Å. In the eighth Co3+ site, Co3+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with three CoO4 tetrahedra and faces with two equivalent BaO12 cuboctahedra. There are a spread of Co–O bond distances ranging from 1.86–2.26 Å. There are thirty inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to three Ba2+, two La3+, and one Co3+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to three Ba2+, two La3+, and one Co3+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to three Ba2+, two La3+, and one Co3+ atom. In the eighth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the tenth O2- site, O2- is bonded in a 6-coordinate geometry to three Ba2+, two La3+, and one Co3+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the twelfth O2- site, O2- is bonded in a 2-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the thirteenth O2- site, O2- is bonded to three Ba2+, one Sr2+, one La3+, and one Co3+ atom to form distorted face-sharing OBa3SrLaCo octahedra. In the fourteenth O2- site, O2- is bonded in a 6-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the fifteenth O2- site, O2- is bonded to three Ba2+, two La3+, and one Co3+ atom to form distorted OBa3La2Co octahedra that share corners with two equivalent OBa3La2Co octahedra and a faceface with one OBa3SrLaCo octahedra. The corner-sharing octahedral tilt angles are 35°. In the sixteenth O2- site, O2- is bonded in a 6-coordinate geometry to three Ba2+, one Sr2+, one La3+, and one Co3+ atom. In the seventeenth O2- site, O2- is bonded to three Ba2+, one Sr2+, one La3+, and one Co3+ atom to form distorted face-sharing OBa3SrLaCo octahedra. In the eighteenth O2- site, O2- is bonded to three Ba2+, two La3+, and one Co3+ atom to form distorted OBa3La2Co octahedra that share corners with two equivalent OBa3La2Co octahedra and a faceface with one OBa3SrLaCo octahedra. The corner-sharing octahedral tilt angles are 35°. In the nineteenth O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, two La3+, and two Co3+ atoms. In the twentieth O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, one Sr2+, one La3+, and two Co3+ atoms. In the twenty-first O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, one Sr2+, one La3+, and two Co3+ atoms. In the twenty-second O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, one Sr2+, one La3+, and two Co3+ atoms. In the twenty-third O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, two La3+, and two Co3+ atoms. In the twenty-fourth O2- site, O2- is bonded in a 6-coordinate geometry to two Ba2+, one Sr2+, one La3+, and two Co3+ atoms. In the twenty-fifth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, two Sr2+, and one Co3+ atom. In the twenty-sixth O2- site, O2- is bonded in a 1-coordinate geometry to two Ba2+, two Sr2+, and one Co3+ atom. In the twenty-seventh O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, two Sr2+, and one Co3+ atom. In the twenty-eighth O2- site, O2- is bonded in a 1-coordinate geometry to two Ba2+, two Sr2+, and one Co3+ atom. In the twenty-ninth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, two Sr2+, and one Co3+ atom. In the thirtieth O2- site, O2- is bonded in a 1-coordinate geometry to three Ba2+, two Sr2+, and one Co3+ atom.