Applying XAS to uncover electron-deficiency multicenter bonding in SnxChy chalcogenides (Ch = 0, S, Se, Te) subjected to high pressure

Electron-deficiency multicenter bonding (EDMB) has been proposed as an incipient, novel chemical bond behind the outstanding properties of promising materials as phase change materials, thermoelectrics, photovoltaic materials and topological insulators. High pressure (HP) can easily induced such EDMB in systems with stereochemically active lone electron pairs (SCALEPs). As we have evidenced for the mixed-valence Sn2S3, XAS has been proved to be an essential technique to unveil these EDMBs, in addition to single-crystal XRD and Raman spectroscopy under HP. This project aims to demonstrate how XAS can be used the emergence of these bonds in other Sn-based chalcogenides. Then, we propose to collect Sn K-edge XAS measurements on SnTe (without SCALEPs), SnSe and Sn3O4 (both with SCALEPs) under HP, up to 50 GPa, to undoubtedly propose the XAS technique as alternative tool to follow the emergence of EDMBs