Materials Data on BaTi4Bi4O15 by Materials Project
BaBi4Ti4O15 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, corners with eight equivalent BiO12 cuboctahedra, faces with two equivalent BiO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, and faces with eight equivalent TiO6 octahedra. There are four shorter (2.76 Å) and eight longer (2.87 Å) Ba–O bond lengths. There are two inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with five TiO6 octahedra and faces with four equivalent BiO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–22°. There are a spread of Ti–O bond distances ranging from 1.78–2.21 Å. In the second Ti4+ site, Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six TiO6 octahedra, faces with four equivalent BaO12 cuboctahedra, and faces with four equivalent BiO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Ti–O bond distances ranging from 1.93–2.09 Å. There are two inequivalent Bi3+ sites. In the first Bi3+ site, Bi3+ is bonded to twelve O2- atoms to form BiO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, corners with four equivalent BiO12 cuboctahedra, a faceface with one BaO12 cuboctahedra, faces with four equivalent BiO12 cuboctahedra, and faces with eight TiO6 octahedra. There are a spread of Bi–O bond distances ranging from 2.52–2.89 Å. In the second Bi3+ site, Bi3+ is bonded in a 4-coordinate geometry to eight O2- atoms. There are four shorter (2.32 Å) and four longer (2.91 Å) Bi–O bond lengths. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ba2+ and two equivalent Ti4+ atoms to form a mixture of distorted edge and corner-sharing OBa4Ti2 octahedra. The corner-sharing octahedral tilt angles are 0°. In the second O2- site, O2- is bonded in a single-bond geometry to one Ti4+ and four equivalent Bi3+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two Ti4+ and four equivalent Bi3+ atoms. In the fourth O2- site, O2- is bonded to four equivalent Bi3+ atoms to form a mixture of edge and corner-sharing OBi4 tetrahedra. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Ti4+ and two equivalent Bi3+ atoms. In the sixth O2- site, O2- is bonded in a distorted linear geometry to two equivalent Ba2+, two equivalent Ti4+, and two equivalent Bi3+ atoms.