RIGOUROUS THEORY FOR NEXAFS: MULTIPLETS and MORE Paul S. Bagus, Chemistry, UNT, Denton, TX Eugene S. Ilton, PNNL, Richland, WA History – Many Body Effects For The Mn 3s XPS in MnO Work Spans Over 3 Decades NEXAFS Selection Rules & Branching Ratios Multiplet Composition of Levels Power & Limitations For NEXAFS Intensities Levels Determine Energies – Multiplets Reflect Intensity Ligand NEXAFS Edges In Actinide Complexes Pre-Edge Structure Reflects Spin-Orbit Splitting In 5f Shell Leads To Major Broadening DOE Support Gratefully Acknowledged 1 Utrecht_2013
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RIGOUROUS THEORY FOR NEXAFS: MULTIPLETS and MORE · RIGOUROUS THEORY FOR NEXAFS: MULTIPLETS and MORE Paul S. Bagus, Chemistry, UNT, Denton, TX Eugene S. Ilton, PNNL, Richland, WA
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RIGOUROUS THEORY FOR NEXAFS: MULTIPLETS and MORE
Paul S. Bagus, Chemistry, UNT, Denton, TX
Eugene S. Ilton, PNNL, Richland, WA
History – Many Body Effects For The Mn 3s XPS in MnO Work Spans Over 3 Decades
NEXAFS Selection Rules & Branching Ratios Multiplet Composition of Levels Power & Limitations For NEXAFS Intensities Levels Determine Energies – Multiplets Reflect Intensity
Ligand NEXAFS Edges In Actinide Complexes Pre-Edge Structure Reflects Spin-Orbit Splitting In 5f Shell Leads To Major Broadening
DOE Support Gratefully Acknowledged 1 Utrecht_2013
Mn 3s XPS IN MnO – 7S & 5S MULTIPLETS Fadley, Shirley, Freeman, Bagus, Mallow, PRL 23 (1969)
Mn2+ Models MnO
Consider Only 7S & 5S Couplings
Large Errors
E Too Large By Factor of 2
Irel Also Too Large By 2x
No Satellites
Error Ascribed To Covalency
“As Expected From Covalent Bonding”
Utrecht_2013 2
3d
Fadley Group Experiment – PRL 1988
Mn atoms, MnO, & MnF2 Similar XPS
or 3s
Relative binding energy (eV)
Utrecht_2013 3
Addition of 3p2 3s3d FACs (Frustrated Auger Configurations)
3d
3p
3s
ACTIVE SPACE: NEAR DEGENERATE Cis Bagus, Freeman, Sasaki, PRL 30 (1973)
Calculated splitting with FAC too small by ~ 2eV
Okada & Kotani: “.. we reduce the radial integral … to 75% of its ab initio value …”
Does Not Explain Why Reduction Needed
Three Decades Later, We Understand
Utrecht_2013 4
INCREASE ACTIVE SPACE FOR Mn 3s XPS Bagus, Broer, and Ilton (2004) – Chem. Phys. Lett.