Materials Data on Tm2GeO5 by Materials Project

Abstract

Tm2GeO5 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Tm3+ sites. In the first Tm3+ site, Tm3+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Tm–O bond distances ranging from 2.17–2.64 Å. In the second Tm3+ site, Tm3+ is bonded to six O2- atoms to form distorted TmO6 octahedra that share corners with four equivalent GeO4 tetrahedra and edges with two equivalent TmO6 octahedra. There are a spread of Tm–O bond distances ranging from 2.18–2.30 Å. Ge4+ is bonded to four O2- atoms to form GeO4 tetrahedra that share corners with four equivalent TmO6 octahedra. The corner-sharing octahedra tilt angles range from 44–71°. There are a spread of Ge–O bond distances ranging from 1.76–1.80 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to four Tm3+ atoms to form distorted edge-sharing OTm4 tetrahedra. In the second O2- site, O2- is bonded in a trigonal non-coplanar geometry to two equivalent Tm3+ and one Ge4+ atom. In the third O2- site, O2- is bonded in a 4-coordinate geometry to three Tm3+ and one Ge4+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to two Tm3+ and one Ge4+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Tm3+ and one Ge4+ atom.