Hybridization peaks in Pt–Cl XANES

Abstract

Ab initio self-consistent X-ray absorption near-edge structure (XANES) calculations for the Pt L 3 edge of (NH 4) 2PtCl 4 and K 2PtCl 6 are in good agreement with experiment. These results allow us to assign a notable postedge XANES feature as a `hybridization peak', i.e., a mixture between the photoelectron state and unoccupied, atomic Cl 3d-states, mediated by multiple-scattering. An analogous interpretation applies to certain `pre-edge' peaks. A characteristic of such peaks is their approximate energy independence, in contrast to X-ray absorption fine-structure peaks. For Pt–Cl compounds, this suggests a way of monitoring the number of neighboring atoms in chemical processes using XANES.