title: Inner-shell photoionization and core-hole decay of Xe and XeF2.
abstract: Photoionization cross sections and partial ion yields of Xe and XeF2 from Xe 3d(5/2), Xe 3d(3/2), and F 1s subshells in the 660-740 eV range are compared to explore effects of the F ligands. The Xe 3d-ϵf continuum shape resonances dominate the photoionization cross sections of both the atom and molecule, but prominent resonances appear in the XeF2 cross section due to nominal excitation of Xe 3d and F 1s electrons to the lowest unoccupied molecular orbital (LUMO), a delocalized anti-bonding MO. Comparisons of the ion products from the atom and molecule following Xe 3d photoionization show that the charge-state distribution of Xe ions is shifted to lower charge states in the molecule along with production of energetic F(+) and F(2+) ions. This suggests that, in decay of a Xe 3d core hole, charge is redistributed to the F ligands and the system dissociates due to Coulomb repulsion. The ion products from excitation of the F 1s-LUMO resonance are different and show strong increases in the yields of Xe(+) and F(+) ions. The subshell ionization thresholds, the LUMO resonance energies, and their oscillator strengths are calculated by relativistic coupled-cluster methods and agree well with measurements.
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Stephen H
authors.initials: SH
authors.lastname: Southworth
authors.affiliation: Synchrotron Radiation Center, University of Wisconsin-Madison, Stoughton, Wisconsin 53589, USA.
authors.forename: Ralf
authors.initials: R
authors.lastname: Wehlitz
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Antonio
authors.initials: A
authors.lastname: Picón
authors.affiliation: X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: C Stefan
authors.initials: CS
authors.lastname: Lehmann
authors.affiliation: Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Lan
authors.initials: L
authors.lastname: Cheng
authors.affiliation: Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Stanton