State-dependent fluorescence yields through the core-valence Coulomb exchange parameter

Total and partial fluorescence yield (PFY) L-edge x-ray absorption spectra differ from the transmission x-ray absorption spectra (XAS) through state-dependent fluorescence yield across the XAS. For 3d to 3d in octahedral symmetry we apply simulations of PFY and XAS and show how the atomic 2p3d Coulomb exchange parameter Gpd governs the differences in the L3/(L2+L3) branching ratio between PFY and XAS. Gpd orders the XAS final states following Hund’s rules creating a strong state-dependent fluorescence decay strength variation across the XAS leading to the differences between PFY and XAS.