Materials Data on Tm2TiO5 by Materials Project

Abstract

Tm2TiO5 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Tm3+ sites. In the first Tm3+ site, Tm3+ is bonded to seven O2- atoms to form distorted TmO7 pentagonal bipyramids that share corners with two equivalent TmO7 hexagonal pyramids, corners with three equivalent TiO5 trigonal bipyramids, edges with three equivalent TmO7 hexagonal pyramids, edges with two equivalent TmO7 pentagonal bipyramids, and edges with two equivalent TiO5 trigonal bipyramids. There are a spread of Tm–O bond distances ranging from 2.25–2.35 Å. In the second Tm3+ site, Tm3+ is bonded to seven O2- atoms to form distorted TmO7 hexagonal pyramids that share corners with two equivalent TmO7 pentagonal bipyramids, a cornercorner with one TiO5 trigonal bipyramid, edges with four equivalent TmO7 hexagonal pyramids, edges with three equivalent TmO7 pentagonal bipyramids, and edges with two equivalent TiO5 trigonal bipyramids. There are a spread of Tm–O bond distances ranging from 2.30–2.34 Å. Ti4+ is bonded to five O2- atoms to form distorted TiO5 trigonal bipyramids that share a cornercorner with one TmO7 hexagonal pyramid, corners with three equivalent TmO7 pentagonal bipyramids, corners with two equivalent TiO5 trigonal bipyramids, edges with two equivalent TmO7 hexagonal pyramids, and edges with two equivalent TmO7 pentagonal bipyramids. There are a spread of Ti–O bond distances ranging from 1.79–1.96 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four Tm3+ atoms to form a mixture of edge and corner-sharing OTm4 tetrahedra. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Tm3+ and one Ti4+ atom. In the third O2- site, O2- is bonded to three Tm3+ and one Ti4+ atom to form distorted OTm3Ti tetrahedra that share corners with nine OTm4 tetrahedra and edges with five OTm3Ti tetrahedra. In the fourth O2- site, O2- is bonded to two Tm3+ and two equivalent Ti4+ atoms to form distorted OTm2Ti2 tetrahedra that share corners with six OTm4 tetrahedra and edges with five OTm3Ti tetrahedra. In the fifth O2- site, O2- is bonded to three Tm3+ and one Ti4+ atom to form OTm3Ti tetrahedra that share corners with nine OTm4 tetrahedra and edges with four OTm3Ti tetrahedra.