Materials Data on SrTi2O5 by Materials Project

Abstract

TiO2SrTiO3 crystallizes in the orthorhombic Cmm2 space group. The structure is two-dimensional and consists of one TiO2SrTiO3 sheet oriented in the (0, 0, 1) direction. there are three inequivalent Sr2+ sites. In the first Sr2+ site, Sr2+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.52 Å) and two longer (2.60 Å) Sr–O bond lengths. In the second Sr2+ site, Sr2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.51–2.65 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 2.55–2.77 Å. There are three inequivalent Ti4+ sites. In the first Ti4+ site, Ti4+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with four equivalent TiO6 octahedra and an edgeedge with one TiO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 14–16°. There are a spread of Ti–O bond distances ranging from 1.85–2.23 Å. In the second Ti4+ site, Ti4+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Ti–O bond distances ranging from 1.82–2.36 Å. In the third Ti4+ site, Ti4+ is bonded to five O2- atoms to form distorted TiO5 trigonal bipyramids that share a cornercorner with one TiO5 trigonal bipyramid and edges with two equivalent TiO6 octahedra. There are a spread of Ti–O bond distances ranging from 1.65–2.09 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent Ti4+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to four Ti4+ atoms. In the third O2- site, O2- is bonded in a single-bond geometry to one Ti4+ atom. In the fourth O2- site, O2- is bonded in a 5-coordinate geometry to two Sr2+ and three Ti4+ atoms. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to two Sr2+ and one Ti4+ atom. In the sixth O2- site, O2- is bonded in a distorted see-saw-like geometry to two Sr2+ and two equivalent Ti4+ atoms. In the seventh O2- site, O2- is bonded in a 5-coordinate geometry to two Sr2+ and three Ti4+ atoms. In the eighth O2- site, O2- is bonded in a trigonal non-coplanar geometry to three Ti4+ atoms. In the ninth O2- site, O2- is bonded in a distorted see-saw-like geometry to two equivalent Sr2+ and two equivalent Ti4+ atoms.