Materials Data on Ba2TiO4 by Materials Project
Ba2TiO4 crystallizes in the orthorhombic Pmm2 space group. The structure is two-dimensional and consists of one Ba2TiO4 sheet oriented in the (0, 0, 1) direction. Ba2+ is bonded to eight O2- atoms to form distorted BaO8 hexagonal bipyramids that share corners with eight equivalent BaO8 hexagonal bipyramids, faces with five equivalent BaO8 hexagonal bipyramids, and faces with four equivalent TiO6 octahedra. There are six shorter (2.81 Å) and two longer (2.82 Å) Ba–O bond lengths. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with four equivalent TiO6 octahedra and faces with eight equivalent BaO8 hexagonal bipyramids. The corner-sharing octahedra tilt angles range from 0–1°. There are a spread of Ti–O bond distances ranging from 1.98–2.00 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Ti4+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to four equivalent Ba2+ and one Ti4+ atom. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent Ba2+ and two equivalent Ti4+ atoms.