| 1. |
- Burmeister, F, et al.
(författare)
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Nonadiabatic effects in photoelectron spectra of HCl and DCl. I. Experiment
- 2002
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Ingår i: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 65:1
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Tidskriftsartikel (refereegranskat)abstract
- The HCl inner-valence photoelectron band at 26 eV binding energy has been recorded at high resolution. Discrete peaks arising from at least two separate vibrational progressions are superimposed on the broad continuum. Fano profiles are visible in one of the progressions. This indicates interference between superimposed electronic states, where weak avoided crossing allows two adiabatic states to couple. In the isotopic DCl molecular spectrum, the discrete lines are less pronounced, due to slower dissociation and therefore less coupling between the continuum and the bound state.
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| 2. |
- Feifel, R, et al.
(författare)
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Observation of a continuum-continuum interference hole in ultrafast dissociating core-excited molecules
- 2000
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Ingår i: Physical Review Letters. - : AIP Publishing. - 0031-9007 .- 1079-7114. ; 85:15, s. 3133-3136
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Tidskriftsartikel (refereegranskat)abstract
- The femtosecond dissociation of HCl after core excitation has been studied through the resonant Auger decay. The spectra contain contributions from decay occurring at both "molecular" and "atomic" internuclear distances. We have observed a new interference mechanism in these spectra: An atomic spectral line develops into a negative spectral contribution, a "hole," when detuning the excitation energy from the maximum of the Cl 2p(-1)sigma* resonance. Resonant x-ray scattering theory quantitatively explains this behavior as due to a novel destructive continuum-Continuum interference between molecular and atomic contributions to the Auger decay.
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| 3. |
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| 4. |
- H. Wang, R. F. Fink, M. N. Piancastelli, M. Bässler, I. Hjelte, O. Björneholm, F. Burmeister, R. Feifel, A. Giertz, C. Miron, S. L. Sorensen, K. Wiesner and S. Svensson
(författare)
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Is there Interference in the Resonant Auger Electron Spectra of N 1s and O 1s -> 2p Core Excited NO?
- 2003
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Ingår i: Chem Phys.. ; :289, s. 31-
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Tidskriftsartikel (refereegranskat)
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| 5. |
- Wang, H, et al.
(författare)
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A vibrationally resolved experimental study of the sulfur L-shell photoelectron spectrum of the CS2 molecule
- 2001
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Ingår i: JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS. - : IOP PUBLISHING LTD. - 0953-4075. ; 34:9, s. 1745-1755 Language: English
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Tidskriftsartikel (refereegranskat)abstract
- The sulfur L-shell photoelectron spectrum of the carbon disulfide molecule has been studied using monochromated synchrotron radiation with a photon energy of 250 eV. The spectrum is atomic like, showing three major bands that can be associated with the su
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| 6. |
- Wang, H., et al.
(författare)
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A vibrationally resolved experimental study of the sulfur L-shell photoelectron spectrum of the CS2 molecule
- 2001
-
Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 34:9, s. 1745-1755
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Tidskriftsartikel (refereegranskat)abstract
- The sulfur L-shell photoelectron spectrum of the carbon disulfide molecule has been studied using monochromated synchrotron radiation with a photon energy of 250 eV. The spectrum is atomic like, showing three major bands that can be associated with the sulfur (2p-1)2P3/2,12 and (2s-1)2S1/2 ionic states. A closer inspection shows that the 2P3/2 state is further split into two components separated by 128 meV due to the molecular field. The resulting ionic states are located at 169.806 eV (0-0 energy), 169.934 eV (0-0 energy), 171.075 eV (0-0 energy) and 237.05 ± 0.2 eV (centroid), respectively. Vibrational progressions in the (2p-1) bands are attributed to the asymmetric v3 mode, which gives evidence of a localization of the core hole. The following values were obtained for the vibrational constants: ωe = 196.7 ± 1.1 meV; ωdxe = 0.2 ± 0.5 meV. A curve fit of the vibrational lines using a Voigt function gave a natural width of 59.6 ± 1.8 meV for the (2p-1) states, corresponding to a lifetime of 11 fs, and a spectrometer broadening of 38.2 ± 1.8 meV. The (2p-1) bands are accompanied by shake-up structures occurring at 6-18 eV higher energies. They are interpreted mainly in terms of excitations to the unoccupied 3πu* orbital in the final ionic state. The (2s-1)2S1/2 band is broad and structureless due to fast Coster-Kronig processes. A fitting of a Voigt function gives a natural line-width of 1.85 eV which corresponds to a lifetime of 0.4 fs.
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| 7. |
- Wang, H., et al.
(författare)
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Filtering core excitation spectra : Vibrationally resolved constant ionic state studies of N 1s → 2π core-excited NO
- 2001
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Ingår i: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 34:22, s. 4417-4426
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Tidskriftsartikel (refereegranskat)abstract
- High-resolution electron spectroscopy studies of the NO molecule in the regions of the N 1s → 2π core excitations have been performed. By selecting electrons within certain binding energy ranges, either the Auger electron yield - a good approximation for the x-ray absorption spectrum - or the electrons emitted after decay to a particular ionic final state (constant ionic state (CIS)) were detected. By selecting the X 1Σ+ (2π0) final state, the superposition of several intermediate state can be disentangled by exploiting a selection rule which permits only two of the three dipole-allowed intermediate states to decay to this specific final state. This makes it possible to obtain more detailed information on the potential energy curves of the intermediate states than is available from regular absorption measurements. We have also obtained CIS spectra for individual vibrational sublevels within this state. The role of lifetime vibrational interference on the appearance of these spectra is discussed.
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| 8. |
- Wang, H, et al.
(författare)
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Is there interference in the resonant Auger electron spectra of N 1s and O 1s -> 2 pi core excited NO?
- 2003
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Ingår i: Chemical Physics. - 0301-0104. ; 289:1, s. 31-44
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Tidskriftsartikel (refereegranskat)abstract
- High-resolution, angle-resolved resonant Auger electron spectra of the NO molecule in the regions of both N and O 1s --> 2pi core electron excitations are presented. A large number of vibrational final states are resolved due to high energy resolution. Calculations based on lifetime vibrational interference (LVI) theory neglecting interference between different electronic intermediate states and between direct and resonant channels have been performed. A comparison between theoretical and experimental spectra shows that LVI theory describes the major spectroscopic features quite well. The same holds for the evolution of the angular averaged partial cross sections with the change of excitation energy. The angular distribution of particular vibrational final states are, however, not described successfully with LVI calculations at the present level of sophistication. A theoretical analysis supports that one reason for this deviation is electronic state interference. (C) 2002 Elsevier Science B.V. All rights reserved.
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