Materials Data on Ca3Ti2O7 by Materials Project
Ca3Ti2O7 is Orthorhombic Perovskite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are two inequivalent Ca2+ sites. In the first Ca2+ site, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.36–2.68 Å. In the second Ca2+ site, Ca2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ca–O bond distances ranging from 2.30–2.56 Å. Ti4+ is bonded to six O2- atoms to form corner-sharing TiO6 octahedra. The corner-sharing octahedra tilt angles range from 21–29°. There are a spread of Ti–O bond distances ranging from 1.92–2.08 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two equivalent Ti4+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to three Ca2+ and two equivalent Ti4+ atoms. In the third O2- site, O2- is bonded in a distorted see-saw-like geometry to three equivalent Ca2+ and one Ti4+ atom. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ca2+ and two equivalent Ti4+ atoms.