Advanced

X-ray absorption and resonant Auger spectroscopy of O(2) in the vicinity of the O 1s-->sigma(*) resonance: Experiment and theory.

Feifel, R; Velkov, Y; Carravetta, V; Angeli, C; Cimiraglia, R; Sałek, P; Gel'mukhanov, F; Ristinmaa Sörensen, Stacey LU ; Piancaśtelli, M N and De Fanis, A, et al. (2008) In Journal of Chemical Physics 128(6).
Abstract
We report on an experimental and theoretical investigation of x-ray absorption and resonant Auger electron spectra of gas phase O(2) recorded in the vicinity of the O 1s-->sigma(*) excitation region. Our investigation shows that core excitation takes place in a region with multiple crossings of potential energy curves of the excited states. We find a complete breakdown of the diabatic picture for this part of the x-ray absorption spectrum, which allows us to assign an hitherto unexplained fine structure in this spectral region. The experimental Auger data reveal an extended vibrational progression, for the outermost singly ionized X (2)Pi(g) final state, which exhibits strong changes in spectral shape within a short range of photon... (More)
We report on an experimental and theoretical investigation of x-ray absorption and resonant Auger electron spectra of gas phase O(2) recorded in the vicinity of the O 1s-->sigma(*) excitation region. Our investigation shows that core excitation takes place in a region with multiple crossings of potential energy curves of the excited states. We find a complete breakdown of the diabatic picture for this part of the x-ray absorption spectrum, which allows us to assign an hitherto unexplained fine structure in this spectral region. The experimental Auger data reveal an extended vibrational progression, for the outermost singly ionized X (2)Pi(g) final state, which exhibits strong changes in spectral shape within a short range of photon energy detuning (0 eV>Omega>-0.7 eV). To explain the experimental resonant Auger electron spectra, we use a mixed adiabatic/diabatic picture selecting crossing points according to the strength of the electronic coupling. Reasonable agreement is found between experiment and theory even though the nonadiabatic couplings are neglected. The resonant Auger electron scattering, which is essentially due to decay from dissociative core-excited states, is accompanied by strong lifetime-vibrational and intermediate electronic state interferences as well as an interference with the direct photoionization channel. The overall agreement between the experimental Auger spectra and the calculated spectra supports the mixed diabatic/adiabatic picture. (Less)
Please use this url to cite or link to this publication:
author
, et al. (More)
(Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Chemical Physics
volume
128
issue
6
publisher
American Institute of Physics
external identifiers
  • pmid:18282035
  • wos:000253238200017
  • scopus:39349091895
ISSN
0021-9606
DOI
10.1063/1.2831920
language
English
LU publication?
yes
id
f04c27f9-d62c-4e7c-b7b4-b139c5b33fe8 (old id 1041781)
date added to LUP
2008-03-26 16:54:40
date last changed
2017-08-27 04:02:30
@article{f04c27f9-d62c-4e7c-b7b4-b139c5b33fe8,
  abstract     = {We report on an experimental and theoretical investigation of x-ray absorption and resonant Auger electron spectra of gas phase O(2) recorded in the vicinity of the O 1s-->sigma(*) excitation region. Our investigation shows that core excitation takes place in a region with multiple crossings of potential energy curves of the excited states. We find a complete breakdown of the diabatic picture for this part of the x-ray absorption spectrum, which allows us to assign an hitherto unexplained fine structure in this spectral region. The experimental Auger data reveal an extended vibrational progression, for the outermost singly ionized X (2)Pi(g) final state, which exhibits strong changes in spectral shape within a short range of photon energy detuning (0 eV>Omega>-0.7 eV). To explain the experimental resonant Auger electron spectra, we use a mixed adiabatic/diabatic picture selecting crossing points according to the strength of the electronic coupling. Reasonable agreement is found between experiment and theory even though the nonadiabatic couplings are neglected. The resonant Auger electron scattering, which is essentially due to decay from dissociative core-excited states, is accompanied by strong lifetime-vibrational and intermediate electronic state interferences as well as an interference with the direct photoionization channel. The overall agreement between the experimental Auger spectra and the calculated spectra supports the mixed diabatic/adiabatic picture.},
  articleno    = {064304},
  author       = {Feifel, R and Velkov, Y and Carravetta, V and Angeli, C and Cimiraglia, R and Sałek, P and Gel'mukhanov, F and Ristinmaa Sörensen, Stacey and Piancaśtelli, M N and De Fanis, A and Okada, K and Kitajima, M and Tanaka, T and Tanaka, H and Ueda, K},
  issn         = {0021-9606},
  language     = {eng},
  number       = {6},
  publisher    = {American Institute of Physics},
  series       = {Journal of Chemical Physics},
  title        = {X-ray absorption and resonant Auger spectroscopy of O(2) in the vicinity of the O 1s-->sigma(*) resonance: Experiment and theory.},
  url          = {http://dx.doi.org/10.1063/1.2831920},
  volume       = {128},
  year         = {2008},
}