| 1. |
|
|
| 2. |
|
|
| 3. |
- Feifel, Raimund, et al.
(författare)
-
Probing the valence character of O-1s -> Rydberg excited O-2 by participator Auger decay measurements and partial ion yield spectroscopy following x-ray absorption
- 2007
-
Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 126:17, s. 174304-
-
Tidskriftsartikel (refereegranskat)abstract
- The valence character of O 1s -> Rydberg excited O-2 is investigated by means of participator Auger decay spectroscopy, performed at selected photon energies across the K-shell resonance region, and by means of partial ion yield x-ray absorption spectroscopy. For several of the excitation energies studied, the authors find substantial sigma(*)((4)Sigma(-)(u),(2)Sigma(-)(u)) valence character being mixed with ns sigma and np sigma ((4)Sigma(-)(u),(2)Sigma(-)(u)) Rydberg states. An experimental indication of a coupling between the channels associated with quartet and doublet ion cores is considered and discussed. New spectroscopic constants are derived for the singly ionized X (2)Pi(g) state of O-2 based on the observation of at least 20 vibrational sublevels.
|
|
| 4. |
- Feifel, R., et al.
(författare)
-
X-ray absorption and resonant Auger spectroscopy of O(2) in the vicinity of the O 1s ->sigma* resonance : Experiment and theory
- 2008
-
Ingår i: Journal of Chemical Physics. - : American Institute of Physics (AIP). - 0021-9606 .- 1089-7690. ; 128:6
-
Tidskriftsartikel (refereegranskat)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.
|
|
| 5. |
- Kitajima, M., et al.
(författare)
-
Angle-resolved photoion yield and resonant Auger spectroscopy for the doubly excited Rydberg states above the C 1s threshold of CO
- 2008
-
Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 78:3, s. 033422-
-
Tidskriftsartikel (refereegranskat)abstract
- Doubly excited core-hole states of carbon monoxide in the photon energy region of 300-305 eV, i.e., directly above the C 1s ionization threshold, have been studied using both angle-resolved ion-yield and high-resolution resonant Auger spectroscopies. The leading configurations of the most prominent doubly excited Rydberg states are assigned by careful analysis of the ion-yield spectra and the final-state spectra to C 1s(-1) (5 sigma(-1)2 pi S-1=1) 3s sigma (v'=0,1,2), C 1s(-1) (5 sigma(-1)2 pi S-1=0) 3s sigma (v'=0,1,2), and C 1s(-1) (5 sigma(-1)2 pi S-1=1) 4s sigma (v'=0,1), which can only be populated via a conjugate shake-up process. Analysis of the resonant Auger spectra provides an assignment of several two-hole-one-electron (2h-1e) final states.
|
|
| 6. |
|
|
| 7. |
- Piancastelli, MN, et al.
(författare)
-
Resonant auger decay of above-threshold core-excited H2O
- 2005
-
Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 71:1
-
Tidskriftsartikel (refereegranskat)abstract
- The decay properties of an above-threshold resonance in core-ionized water, which is difficult to. identify with usual spectroscopic methods, have been analyzed by resonant Auger spectroscopy. The resonance is. shown to correspond to a doubly excited neutral state embedded in the O 1s ionization continuum. The main, result of the experiments is the assessment on the dissociative nature of the intermediate state, with a consequent fragmentation in H neutral plus O*H core excited. This dissociation takes place on the same time scale.. as electron decay, and therefore is categorized as an ultrafast. dissociation process.
|
|
| 8. |
- Sankari, R, et al.
(författare)
-
High resolution O 1s photoelectron shake-up satellite spectrum of H2O
- 2006
-
Ingår i: Chemical Physics Letters. - : Elsevier BV. - 0009-2614. ; 422:1-3, s. 51-57
-
Tidskriftsartikel (refereegranskat)abstract
- The O 1s photoelectron satellite spectrum of water has been recorded with high resolution and some vibrational structures were detected. The electronic and vibrational structures observed in the experimental spectrum are well interpreted with the aid of the molecular ab initio calculations based on the symmetry adapted cluster-configuration interaction (SAC-CI) method. (c) 2006 Elsevier B.V. All rights reserved.
|
|
| 9. |
- Sorensen, S. L., et al.
(författare)
-
The O 1s photoelectron spectrum of molecular oxygen revisited
- 2008
-
Ingår i: Journal of Physics B. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 41:9, s. 095101-
-
Tidskriftsartikel (refereegranskat)abstract
- High-resolution photoelectron spectra of the inner-shell levels of molecular oxygen have been measured using synchrotron radiation. The vibrational structure of the two magnetically-split core-shell components is analyzed based upon ab initio calculations. The ratio between the intensities of the two components was analyzed at several different ionization energies up to about 600 eV, and the same is discussed and compared to high-energy ionization intensities. A theoretical calculation shows very good agreement with the measured spectra. The calculation implements a model where two parity components make up the 4Σ peak profile. The gerade-ungerade energy split for this state is found to be 50 meV.
|
|
| 10. |
- Tanaka, T., et al.
(författare)
-
Symmetry-resolved x-ray absorption fine structure and resonant Auger-spectator-electron decay study of O 1s→Rydberg resonances in O2
- 2008
-
Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 78:2, s. 022516-
-
Tidskriftsartikel (refereegranskat)abstract
- A series of resonant Auger-electron spectra excited at selected photon energies across the O 1s -> Rydberg resonances in O-2 has been measured. Applying a spectator-electron shake relaxation model originally introduced for atomic resonant Auger-electron spectra, and using, to a large extent, the assignments for the core-excited resonances available from the literature, many of the observed spectator Auger-electron final states are assigned in terms of cationic Rydberg series. Vice versa the resonant Auger-electron spectra are used for consistency tests of the literature assignments for the core-excited intermediate Rydberg states. For some of the latter, alternative assignments are proposed for reasons discussed.
|
|
