Materials Data on Ba2La4Ti5O18 by Materials Project
La4Ba2Ti5O18 crystallizes in the trigonal R3 space group. The structure is three-dimensional. there are two 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 LaO12 cuboctahedra, and faces with seven TiO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.72–2.90 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with nine BaO12 cuboctahedra, faces with six LaO12 cuboctahedra, and faces with eight TiO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.80–2.82 Å. There are four inequivalent La3+ sites. In the first La3+ site, La3+ is bonded to twelve O2- atoms to form distorted LaO12 cuboctahedra that share corners with nine LaO12 cuboctahedra, faces with three equivalent BaO12 cuboctahedra, and faces with seven TiO6 octahedra. There are a spread of La–O bond distances ranging from 2.50–2.97 Å. In the second La3+ site, La3+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of La–O bond distances ranging from 2.49–2.84 Å. In the third La3+ site, La3+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of La–O bond distances ranging from 2.49–2.97 Å. In the fourth La3+ site, La3+ is bonded to twelve O2- atoms to form LaO12 cuboctahedra that share corners with nine LaO12 cuboctahedra, faces with six BaO12 cuboctahedra, and faces with eight TiO6 octahedra. There are a spread of La–O bond distances ranging from 2.64–2.89 Å. There are five inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with three equivalent TiO6 octahedra, a faceface with one LaO12 cuboctahedra, and faces with three equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 12°. There are three shorter (1.85 Å) and three longer (2.18 Å) Ti–O bond lengths. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with three equivalent TiO6 octahedra, a faceface with one BaO12 cuboctahedra, and faces with three equivalent LaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There is three shorter (1.89 Å) and three longer (2.09 Å) Ti–O bond length. In the third Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra, faces with four BaO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–3°. There is three shorter (1.96 Å) and three longer (1.99 Å) Ti–O bond length. In the fourth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra, faces with three equivalent LaO12 cuboctahedra, and faces with four BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 3–12°. There is three shorter (1.90 Å) and three longer (2.06 Å) Ti–O bond length. In the fifth Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra, faces with three equivalent BaO12 cuboctahedra, and faces with four LaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 2–3°. There is three shorter (1.95 Å) and three longer (2.00 Å) Ti–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to two equivalent Ba2+, one La3+, and two Ti4+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to one Ba2+, three La3+, and two Ti4+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two Ba2+, two equivalent La3+, and two Ti4+ atoms. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+, two La3+, and two Ti4+ atoms. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to one Ba2+, three La3+, and one Ti4+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to four La3+ and one Ti4+ atom.