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- Baev, A, et al.
(author)
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Picturing molecular femtosecond processes through an ultra-fast controllable X-ray shutter
- 2003
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In: Chemical Physics. - 0301-0104 .- 1873-4421. ; 289, s. 51-56
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Journal article (peer-reviewed)abstract
- We show that frequency detuning in a resonant X-ray scattering experiment acts as an X-ray camera shutter by regulating the duration time of the scattering process. The camera shutter can be used to select processes at different time scales for observation. This is illustrated by a resonant Auger study of the ultra-fast dissociation of the core-excited HF molecule. We present experimental results and first principle simulations of the molecular fraction in the resonant Auger spectra of HF which is a dynamical parameter that well illustrates X-ray shutter controlled dissociation.
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- Bueno, AM, et al.
(author)
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Influence of chemical bonds on the lifetime of the molecular-field-split 2p levels in H2S
- 2003
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 67, s. 22714:1-7
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Journal article (peer-reviewed)abstract
- Different lifetime broadenings in molecular-field-split 2p core levels in H2S are predicted theoretically and are identified in an experimental investigation of the S 2p Auger electron spectrum. The measurements were performed for the transition to the vibrationally resolved X(1)A(1) ground state of H2S2+. The lifetimes of the 3e(1/2) and 5e(1/2) levels of the 2p ionized molecule are found to be 64 and 74 meV, respectively. This unambiguous determination of the lifetime difference of 10+/-1 meV is only possible as the 4e(1/2)-->X(1)A(1)(2b(1)(-2)) decay channel that overlaps the 5e(1/2)-->X(1)A(1)(2b(1)(-2)) channel is practically suppressed in Auger decay in H2S. The lifetime difference is confirmed by ab initio calculations. A theoretical analysis shows that it results from the mutual orientation of the core hole in the intermediate states and the valence electron density in the sulfur 3p orbitals. Both are strongly influenced by the chemical bond. Thus the observed effect is the direct result of a fundamental property of molecular electronic structure.
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- Feifel, Raimund, et al.
(author)
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From localised to delocalised electronic states in free Ar, Kr and Xe clusters
- 2004
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In: European Physical Journal D. Atomic, Molecular, Optical and Plasma Physics. - : Springer Science and Business Media LLC. - 1434-6060 .- 1434-6079. ; 30:3, s. 343-351
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Journal article (peer-reviewed)abstract
- We present new results for the inner valence levels of clusters of the three inert gases Ar, Kr and Xe based on photoelectron spectroscopy studies. The inner valence levels are compared to the localised core levels and to the delocalised outer valence levels. This comparison shows a gradual change from a relatively localised behaviour for Ar inner valence 3s, over the intermediate case of Kr inner valence 4s, to a more delocalised behaviour for Xe inner valence 5s. This change correlates well with the ratio between the orbital sizes and the interatomic distances. The Kr4s intermediate case is found to exhibit characteristics of both localised and delocalised behaviour.
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