Materials Data on Ge(SbTe2)2 by Materials Project

Abstract

Ge(SbTe2)2 crystallizes in the tetragonal I-4m2 space group. The structure is three-dimensional. Ge4+ is bonded to six Te2- atoms to form GeTe6 octahedra that share corners with two equivalent SbTe6 octahedra, corners with four equivalent GeTe6 octahedra, and edges with eight SbTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (3.00 Å) and four longer (3.06 Å) Ge–Te bond lengths. There are two inequivalent Sb2+ sites. In the first Sb2+ site, Sb2+ 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 four equivalent GeTe6 octahedra, and edges with four equivalent SbTe6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are two shorter (3.05 Å) and four longer (3.06 Å) Sb–Te bond lengths. In the second Sb2+ site, Sb2+ is bonded to six Te2- atoms to form SbTe6 octahedra that share corners with four equivalent SbTe6 octahedra, edges with four equivalent GeTe6 octahedra, and edges with four equivalent SbTe6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are two shorter (3.05 Å) and four longer (3.06 Å) Sb–Te bond lengths. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to two equivalent Ge4+ and three Sb2+ atoms to form a mixture of edge and corner-sharing TeGe2Sb3 square pyramids. In the second Te2- site, Te2- is bonded in a square co-planar geometry to one Ge4+ and three Sb2+ atoms.