| 1. |
|
|
| 2. |
- Brena, Barbara, et al.
(författare)
-
Equivalent core-hole time-dependent density functional theory calculations of carbon 1s shake-up states of phthalocyanine
- 2004
-
Ingår i: Physical Review B. Condensed Matter and Materials Physics. - 1098-0121 .- 1550-235X. ; 70:19, s. 195214-
-
Tidskriftsartikel (refereegranskat)abstract
- The shake-up transition energies of the carbon 1s photoelectron spectrum of metal-free phthalocyanine (H2Pc) have been calculated by means of time-dependent density functional theory, for which an equivalent core approximation is adopted. Model calculations for the C 1s shake-up states of benzene are in excellent agreement with the latest experimental results. The complex C 1s shake-up structures associated with the aromatic and pyrrole carbons in the phthalocyanine are computed, as well as their ionization potentials. They allow us to determine the origin of the anomalous intensity ratio between the pyrrole and benzene carbons in a high resolution C 1s photoelectron spectrum measured for a H2Pc film, as due to a benzene-related shake-up contribution, hidden under the pyrrole main intensity feature.
|
|
| 3. |
- Capron, Nathalie, et al.
(författare)
-
Correction: Probing keto–enol tautomerism using photoelectron spectroscopy
- 2018
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 20:1, s. 695-695
-
Tidskriftsartikel (refereegranskat)abstract
- Correction for ‘Probing keto–enol tautomerism using photoelectron spectroscopy’ by Nathalie Capron et al., Phys. Chem. Chem. Phys., 2015, 17, 19991–19996.
|
|
| 4. |
- Capron, Nathalie, et al.
(författare)
-
Probing keto-enol tautomerism using photoelectron spectroscopy
- 2015
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 17:30, s. 19991-19996
-
Tidskriftsartikel (refereegranskat)abstract
- We theoretically investigate the mechanism of tautomerism in the gas-phase acetylacetone molecule. The minimum energy path between the enolone and diketo forms has been computed using the Nudged-Elastic Band (NEB) method within the density-functional theory (DFT) using the projector augmented-wave method and generalized gradient approximation in Perdew-Wang (PW91) parametrization. The lowest transition state as well as several intermediate geometries between the two stable tautomers have been identified. The outer-valence ionization spectra for all determined geometries have been computed using the third-order non-Dyson algebraic diagrammatic construction technique. Furthermore, the oxygen core-shell ionization spectra for these geometries have been obtained using DFT and the Becke three-parameter Lee-Yang-Parr (B3LYP) functional. It is shown that all spectra depend strongly on the geometries demonstrating the possibility of following the proton-transfer dynamics using photoelectron spectroscopy in pump-probe experiments.
|
|
| 5. |
- Carniato, Stéphane, et al.
(författare)
-
N-K near edge x-ray absorption fine structures of acetonitrile in gas phase
- 2005
-
Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 123:21, s. 214301-
-
Tidskriftsartikel (refereegranskat)abstract
- The dynamic processes of N(1s) core-hole excitation in gas-phase CH3CN molecule have been studied at both Hartree-Fock and hybrid density-functional theory levels. The vibrational structure is analyzed for fully optimized core-excited states. Frank-Condon factors are obtained using the linear coupling model for various potential surfaces. It is found that the vibrational profile of the N-K absorption can be largely described by a summation of two vibrational progressions: a structure-rich profile of nu((CN)) stretching mode and a large envelope of congestioned vibrational levels related to the strong (-C-CN) terminal bending bond. Excellent agreement between theoretical and experimental spectra is obtained.
|
|
| 6. |
- Carniato, Stéphane, et al.
(författare)
-
Resonant X-ray Raman scattering on molecules : A benchmark study on HCl
- 2010
-
Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 181:2-3, s. 116-120
-
Tidskriftsartikel (refereegranskat)abstract
- Resonant X-ray Raman scattering is a powerful tool to study molecular dynamics and subtle chemical effects like the molecular field beyond vibrational and lifetime limitations. Using this technique in the tender X-ray region, gas phase HCl is studied as a benchmark molecule for other compounds like freons, which play an important role in physical-chemical properties of the ozone layer of atmosphere.
|
|
| 7. |
- Gavrilyuk, Sergey, 1972-
(författare)
-
Molecular electronic, vibrational and rotational motion in optical and x-ray fields
- 2009
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The subject of this theoretical study is the role ofelectronic structure as well as of rotational and vibrational motionson interactions between molecules and electromagnetic radiation,ranging from optical to x-ray. The thesis concerns both linear and nonlinear regimes of the light-matter interaction. The first part of the thesis is devoted to propagation of opticalpulses with different time-structure through various nonlinear absorbers.First we explain the double-exponential decay of fluorescence caused by photobleaching of pyrylium salt irradiated by a train of short (100 fs) optical pulses. The main reason for this effect is the transversal inhomogeneity of the light beam which makes the dynamics of the photobleaching differ in the core of the pulse and on its periphery. We also explore the optical power limitingof C60 fullerene irradiated by either microsecond optical pulses or a picosecond pulse trains. Enhancement of nonlinear absorption is caused by strong triplet-triplet absorption that becomes important due toelongation of the interaction time.Here we show the importance of the repetitionrate for the optical power limiting performance.The second part of the thesis addresses the interaction of optical and x-rayfields with rotational degrees of freedom of molecules. In this part the main attention is paid to the rotational heating caused by the recoil, experienced by molecules due to the ejection of photoelectrons. We have quantitatively explained two qualitatively different experiments with the N2 molecule.We predict the interference modulation of the recoil-induced shift,which is a shift of the photoelectron line caused by the rotational recoil effect, as a function of the photon energy.The developed theory also explains the rotational heating ofmolecules observed in the optical fluorescence induced by x-ray radiation.Based on this explanation, we suggest a new scheme of the optical fluorescence induced by x-rays that allows to detect the recoil effect via the recoil-inducedsplitting of the optical resonance.The last part of the thesis focuses on multi-mode nuclear dynamics of the resonant Auger scattering from the C2H2 molecule, that was the subject of a recent experimental study.Here we develop a theory that explains the observed vibrationalscattering anisotropy. We have found that three qualitatively different mechanisms are responsible for this phenomenon. The first mechanism is the interference of the direct and resonance scattering channels. The second mechanismis the interference of the resonant scattering channels through core excitedstate with the orthogonal orientation of the vibrational modes of core excitedstate. The Young's double slit like interference of the quantum pathways through the double-well potential of the bending motion of core excited state is the third mechanism of the vibrational scattering anisotropy.
|
|
| 8. |
- Guillemin, Renaud, et al.
(författare)
-
A review of molecular effects in gas-phase KL X-ray emission
- 2013
-
Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 188, s. 53-61
-
Forskningsöversikt (refereegranskat)abstract
- The unique capabilities of resonant inelastic X-ray scattering (RIXS) to provide a deep insight into molecular dynamics following core excitation are reviewed here. Characteristic features of molecular X-ray emission are experimentally observed and theoretically interpreted. Some of our most significant results on molecular dynamics following deep core excitation are presented. In particular, we provide several examples of nuclear dynamics on the femtosecond or subfemtosecond time scale; line-narrowing effects related to the quenching of vibrational structure due to parallelism of intermediate and final state curves; anomalous line dispersion across a resonance, which is due to core-hole lifetime effects; spin–orbit-state populations derived from polarized RIXS experiments. We also show how to connect the RIXS results to the general chemical properties of the investigated systems.
|
|
| 9. |
- Guillemin, Renaud, et al.
(författare)
-
Angular and dynamical properties in resonant inelastic x-ray scattering : Case study of chlorine-containing molecules
- 2012
-
Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 86:1
-
Tidskriftsartikel (refereegranskat)abstract
- Polarization-dependent resonant inelastic x-ray scattering (RIXS) has been shown to be a probe of molecular-field effects on the electronic structure of isolated molecules. In this experimental analysis we explain the linear dichroism observed in Cl 2p polarized RIXS following Cl 1s excitation of a series of chlorofluoromethanes (CF3Cl, CF2Cl2, CFCl3, and CCl4) as due to molecular-field effects, including singlet-triplet exchange. We present an approach to extract directly the 2p inner-shell electronic state populations from the experimental measurements. Using the angular properties of the measured KV emission we also are able to determine the value of the polarization anisotropy parameter beta(p) for each resolved component of the KV emission spectra.
|
|
| 10. |
- Kawerk, Elie, et al.
(författare)
-
Experimental and theoretical study of X-ray absorption around the chlorine L edge in vinyl chloride
- 2013
-
Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 186, s. 1-7
-
Tidskriftsartikel (refereegranskat)abstract
- We present a combined experimental and theoretical study of the high-resolution chlorine L edge X-ray absorption spectrum in gas-phase vinyl chloride (C2H3Cl). With the help of ab-initio calculations, we interpret the experimental spectrum and attribute each band to its corresponding electronic transitions terminating at states characterized by an either binding or dissociative potential energy surface (PES). Vibrational substructures in some specific core-excited electronic states are taken into account.
|
|
