Materials Data on Tm5(GeSb)2 by Materials Project

Abstract

Tm5(GeSb)2 crystallizes in the orthorhombic Cmce space group. The structure is three-dimensional. there are two inequivalent Tm sites. In the first Tm site, Tm is bonded to three equivalent Ge and three equivalent Sb atoms to form distorted TmGe3Sb3 pentagonal pyramids that share corners with three equivalent TmGe4Sb2 octahedra, corners with ten equivalent TmGe3Sb3 pentagonal pyramids, edges with seven equivalent TmGe3Sb3 pentagonal pyramids, faces with two equivalent TmGe4Sb2 octahedra, and faces with two equivalent TmGe3Sb3 pentagonal pyramids. The corner-sharing octahedra tilt angles range from 36–42°. There are one shorter (2.90 Å) and two longer (3.04 Å) Tm–Ge bond lengths. There are a spread of Tm–Sb bond distances ranging from 3.09–3.15 Å. In the second Tm site, Tm is bonded to four equivalent Ge and two equivalent Sb atoms to form TmGe4Sb2 octahedra that share corners with four equivalent TmGe4Sb2 octahedra, corners with twelve equivalent TmGe3Sb3 pentagonal pyramids, and faces with eight equivalent TmGe3Sb3 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. There are two shorter (3.02 Å) and two longer (3.04 Å) Tm–Ge bond lengths. Both Tm–Sb bond lengths are 3.07 Å. Ge is bonded in a 8-coordinate geometry to eight Tm atoms. Sb is bonded to seven Tm atoms to form a mixture of distorted corner and edge-sharing SbTm7 pentagonal bipyramids.