Materials Data on SnGe4Te4Se by Materials Project

Abstract

SnGe4Te4Se is Caswellsilverite-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Sn2+ is bonded in a 6-coordinate geometry to three equivalent Te2- and three equivalent Se2- atoms. All Sn–Te bond lengths are 3.47 Å. All Sn–Se bond lengths are 2.84 Å. There are four inequivalent Ge2+ sites. In the first Ge2+ site, Ge2+ is bonded to three equivalent Te2- and three equivalent Se2- atoms to form GeTe3Se3 octahedra that share corners with three equivalent GeTe6 octahedra and edges with nine GeTe3Se3 octahedra. The corner-sharing octahedral tilt angles are 10°. There are one shorter (2.84 Å) and two longer (2.85 Å) Ge–Te bond lengths. There are two shorter (3.11 Å) and one longer (3.12 Å) Ge–Se bond lengths. In the second Ge2+ site, Ge2+ is bonded to six Te2- atoms to form a mixture of edge and corner-sharing GeTe6 octahedra. The corner-sharing octahedral tilt angles are 10°. There are a spread of Ge–Te bond distances ranging from 2.84–3.25 Å. In the third Ge2+ site, Ge2+ is bonded to six Te2- atoms to form a mixture of edge and corner-sharing GeTe6 octahedra. The corner-sharing octahedral tilt angles are 10°. There are a spread of Ge–Te bond distances ranging from 2.84–3.25 Å. In the fourth Ge2+ site, Ge2+ is bonded to six Te2- atoms to form a mixture of edge and corner-sharing GeTe6 octahedra. The corner-sharing octahedral tilt angles are 10°. There are a spread of Ge–Te bond distances ranging from 2.84–3.25 Å. There are four inequivalent Te2- sites. In the first Te2- site, Te2- is bonded to six Ge2+ atoms to form TeGe6 octahedra that share corners with three equivalent TeGe6 octahedra, corners with three equivalent SeSn3Ge3 octahedra, edges with three equivalent SeSn3Ge3 octahedra, and edges with nine TeGe6 octahedra. The corner-sharing octahedra tilt angles range from 7–10°. In the second Te2- site, Te2- is bonded to six Ge2+ atoms to form a mixture of edge and corner-sharing TeGe6 octahedra. The corner-sharing octahedral tilt angles are 10°. In the third Te2- site, Te2- is bonded to six Ge2+ atoms to form a mixture of edge and corner-sharing TeGe6 octahedra. The corner-sharing octahedral tilt angles are 10°. In the fourth Te2- site, Te2- is bonded to three equivalent Sn2+ and three equivalent Ge2+ atoms to form distorted TeSn3Ge3 octahedra that share corners with three equivalent TeGe6 octahedra, corners with three equivalent SeSn3Ge3 octahedra, edges with three equivalent SeSn3Ge3 octahedra, and edges with nine TeGe6 octahedra. The corner-sharing octahedra tilt angles range from 10–14°. Se2- is bonded to three equivalent Sn2+ and three equivalent Ge2+ atoms to form SeSn3Ge3 octahedra that share corners with six TeGe6 octahedra, edges with six TeGe6 octahedra, and edges with six equivalent SeSn3Ge3 octahedra. The corner-sharing octahedra tilt angles range from 7–14°.