Materials Data on Tm2Si2O7 by Materials Project

Abstract

Tm2Si2O7 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Tm3+ is bonded to six O2- atoms to form distorted TmO6 octahedra that share corners with six equivalent SiO4 tetrahedra and edges with three equivalent TmO6 octahedra. There are a spread of Tm–O bond distances ranging from 2.22–2.30 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with six equivalent TmO6 octahedra and a cornercorner with one SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 49–58°. There is two shorter (1.64 Å) and two longer (1.65 Å) Si–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Tm3+ and one Si4+ atom. In the second O2- site, O2- is bonded in a linear geometry to two equivalent Si4+ atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Tm3+ and one Si4+ atom.