PNNL

Abstract

A strict ab initio model of the many body effects for the free Cr3+ ion is developed in order to provide a new benchmark for intra-atomic effects in the XP spectra of Cr3+ compounds. The model contains no empirical fits or assumptions and incorporates all inter and intra shell couplings and recouplings, relativistic orbitals, spin-orbital coupling , the core hole, and Boltzmann weighted averages for initial state spin-orbit split levels. Synthetic Cr2p and 3p XP spectra are compared to an experimental spectrum of a-Cr2O3. The theory for the free Cr ion accounts for important features of the experimental Cr2p spectrum, including the spin-orbital splitting energy and the Cr2p3/2 doublet. In contrast, the theory only accounts for the grossest features of the experimental Cr3p spectrum. Comparing experiment with theory highlights the importance of both intra- and inter atomic effects on the XP spectra of Cr3+ compounds.