Hybridization peaks in Pt-Cl XANES

Ab initio self-consistent X-ray absorption near-edge structure (XANES) calc ulations for the Pt L-3 edge of (NH4)(2)PtCl4 and K2PtCl6 are in good agree ment with experiment. These results allow us to assign a notable postedge X ANES feature as a 'hybridization peak', i.e., a mixture between the photoel ectron state and unoccupied, atomic Cl 3d-states, mediated by multiple-scat tering An analogous interpretation applies to certain 'pre-edge' peaks. A c haracteristic of such peaks is their approximate energy independence, in co ntrast to X-ray absorption fine-structure peaks. For Pt-Cl compounds, this suggests a way of monitoring the number of neighboring atoms in chemical pr ocesses using XANES. (C) 2000 Elsevier Science B.V. All rights reserved.