Intra-atomic many-body effects inp-shell photoelectron spectra ofCr3+ions

Abstract

A strict ab initio model of the many-body effects for the free ${\mathrm{Cr}}^{3+}$ ion is developed in order to provide a benchmark for intra-atomic effects in the XP spectra of ${\mathrm{Cr}}^{3+}$ compounds. The model contains no empirical fits or assumptions and incorporates all intershell and intrashell couplings and recouplings, relativistic orbitals, spin-orbital coupling, the core hole, and Boltzmann weighted averages for initial state spin-orbit split levels. Synthetic Cr $2p$ and $3p$ XP spectra are compared to an experimental spectrum of $\alpha -{\mathrm{Cr}}_2{\mathrm{O}}_3.$ The theory for the free Cr ion accounts for important features of the experimental Cr $2p$ spectrum, including the spin-orbital splitting energy and the Cr ${2p}_{3/2}$ doublet. In contrast, the theory only accounts for the grossest features of the experimental Cr $3p$ spectrum. Comparing experiment with theory highlights the importance of both intra-atomic and inter-atomic effects on the XP spectra of ${\mathrm{Cr}}^{3+}$ compounds.