DOE OSTI2020
As2Te3 crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of two As2Te3 sheets oriented in the (1, 0, 0) direction. there are two inequivalent As3- sites. In the first As3- site, As3- is bonded to five Te2+ atoms to form distorted AsTe5 square pyramids that share corners with two equivalent AsTe6 octahedra, edges with three equivalent AsTe6 octahedra, and edges with four equivalent AsTe5 square pyramids. The corner-sharing octahedral tilt angles are 4°. There are a spread of As–Te bond distances ranging from 2.67–3.26 Å. In the second As3- site, As3- is bonded to six Te2+ atoms to form AsTe6 octahedra that share corners with two equivalent AsTe5 square pyramids, edges with four equivalent AsTe6 octahedra, and edges with three equivalent AsTe5 square pyramids. There are a spread of As–Te bond distances ranging from 2.81–2.99 Å. There are three inequivalent Te2+ sites. In the first Te2+ site, Te2+ is bonded in a distorted T-shaped geometry to three As3- atoms. In the second Te2+ site, Te2+ is bonded to five As3- atoms to form distorted edge-sharing TeAs5 square pyramids. In the third Te2+ site, Te2+ is bonded in a distorted T-shaped geometry to three equivalent As3- atoms.