Materials Data on Ge3(SbTe3)2 by Materials Project

Abstract

Ge3Sb2Te6 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to six Te2- atoms to form GeTe6 octahedra that share corners with four equivalent GeTe6 octahedra, edges with five GeTe6 octahedra, and edges with five equivalent SbTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. There are a spread of Ge–Te bond distances ranging from 2.92–3.09 Å. In the second Ge4+ site, Ge4+ is bonded to six Te2- atoms to form GeTe6 octahedra that share corners with two equivalent GeTe6 octahedra, corners with four equivalent SbTe6 octahedra, edges with four equivalent SbTe6 octahedra, and edges with six equivalent GeTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Ge–Te bond distances ranging from 2.97–3.05 Å. Sb is bonded to six Te2- atoms to form SbTe6 octahedra that share corners with two equivalent GeTe6 octahedra, corners with four equivalent SbTe6 octahedra, edges with two equivalent SbTe6 octahedra, and edges with seven GeTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Sb–Te bond distances ranging from 3.01–3.09 Å. There are four inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to four Ge4+ and one Sb atom to form TeGe4Sb square pyramids that share corners with five TeGe4Sb square pyramids, edges with three equivalent TeGe4Sb2 octahedra, and edges with five TeGe4Sb square pyramids. In the second Te2- site, Te2- is bonded to four Ge4+ and two equivalent Sb atoms to form TeGe4Sb2 octahedra that share corners with two equivalent TeGe4Sb2 octahedra, corners with four equivalent TeGe2Sb3 square pyramids, and edges with ten TeGe4Sb square pyramids. The corner-sharing octahedral tilt angles are 0°. In the third Te2- site, Te2- is bonded to two Ge4+ and three equivalent Sb atoms to form TeGe2Sb3 square pyramids that share corners with two equivalent TeGe4Sb2 octahedra, corners with five TeGe4Sb square pyramids, edges with two equivalent TeGe4Sb2 octahedra, and edges with five TeGe4Sb square pyramids. The corner-sharing octahedra tilt angles range from 0–1°. In the fourth Te2- site, Te2- is bonded in a square co-planar geometry to two equivalent Ge4+ and two equivalent Sb atoms.