Materials Data on Ge(Te2As)2 by Materials Project

Abstract

As2Te3(GeTe) is MAX Phase-like structured and crystallizes in the trigonal R-3m space group. The structure is two-dimensional and consists of three As2Te3(GeTe) sheets oriented in the (0, 0, 1) direction. Ge4+ is bonded to six equivalent Te2- atoms to form GeTe6 octahedra that share corners with six equivalent AsTe6 octahedra, edges with six equivalent GeTe6 octahedra, and edges with six equivalent AsTe6 octahedra. The corner-sharing octahedral tilt angles are 1°. All Ge–Te bond lengths are 2.97 Å. As2+ is bonded to six Te2- atoms to form AsTe6 octahedra that share corners with three equivalent GeTe6 octahedra, edges with three equivalent GeTe6 octahedra, and edges with six equivalent AsTe6 octahedra. The corner-sharing octahedral tilt angles are 1°. There are three shorter (2.85 Å) and three longer (3.03 Å) As–Te bond lengths. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent As2+ atoms. In the second Te2- site, Te2- is bonded to three equivalent Ge4+ and three equivalent As2+ atoms to form a mixture of corner and edge-sharing TeGe3As3 octahedra. The corner-sharing octahedral tilt angles are 0°.