Materials Data on Ge2Sb2Te5 by Materials Project

Abstract

Ge2Sb2Te5 crystallizes in the monoclinic Cm 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 two SbTe6 octahedra, corners with three GeTe6 octahedra, edges with three equivalent GeTe6 octahedra, and edges with six SbTe6 octahedra. The corner-sharing octahedra tilt angles range from 2–7°. There are a spread of Ge–Te bond distances ranging from 2.85–3.20 Å. In the second Ge4+ site, Ge4+ is bonded to six Te2- atoms to form GeTe6 octahedra that share corners with two SbTe6 octahedra, corners with three GeTe6 octahedra, edges with three equivalent GeTe6 octahedra, and edges with six SbTe6 octahedra. The corner-sharing octahedra tilt angles range from 1–4°. There are a spread of Ge–Te bond distances ranging from 2.82–3.19 Å. There are two inequivalent Sb1+ sites. In the first Sb1+ site, Sb1+ is bonded to six Te2- atoms to form SbTe6 octahedra that share corners with two GeTe6 octahedra, corners with three SbTe6 octahedra, edges with three equivalent SbTe6 octahedra, and edges with six GeTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Sb–Te bond distances ranging from 2.98–3.20 Å. In the second Sb1+ site, Sb1+ is bonded to six Te2- atoms to form SbTe6 octahedra that share corners with two GeTe6 octahedra, corners with three SbTe6 octahedra, edges with three equivalent SbTe6 octahedra, and edges with six GeTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–4°. There are a spread of Sb–Te bond distances ranging from 2.95–3.19 Å. There are five inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to two Ge4+ and three Sb1+ atoms to form TeGe2Sb3 square pyramids that share corners with six TeGe2Sb3 square pyramids and edges with seven TeGe3Sb2 square pyramids. In the second Te2- site, Te2- is bonded in a rectangular see-saw-like geometry to two Ge4+ and two Sb1+ atoms. In the third Te2- site, Te2- is bonded to three Ge4+ and two Sb1+ atoms to form TeGe3Sb2 square pyramids that share corners with six TeGe3Sb2 square pyramids and edges with seven TeGe2Sb3 square pyramids. In the fourth Te2- site, Te2- is bonded to three Ge4+ and two Sb1+ atoms to form a mixture of corner and edge-sharing TeGe3Sb2 square pyramids. In the fifth Te2- site, Te2- is bonded to two Ge4+ and three Sb1+ atoms to form a mixture of corner and edge-sharing TeGe2Sb3 square pyramids.