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I Hjelte,
L Karlsson,
S Svensson,
A De Fanis,
V Carravetta,
N Saito,
M Kitajima,
H Tanaka, H Yoshida,
A Hiraya,
I Koyano,
K Ueda,
M N Piancastelli
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ABSTRACT: Vibrationally resolved spectra have been obtained for the lowest-lying cationic states X (2)B(1), A (2)A(1), and B (2)B(2) of the water molecule reached after participator resonant Auger decay of core-excited states. The angular distribution has been measured of the first four vibrational components of the X state in the photon energy regions including the O 1s-->4a(1) and the O 1s-->2b(2) core excitations, and for different portions of the vibrational envelope of the B state in the photon energy region including the O 1s-->2b(2) core excitation. For the X state, a large relative spread in beta values of the different vibrational components is observed across both resonances. For the B state, a very different trend is observed for the high binding energy side and the low binding energy side of the related spectral feature as a function of photon energy. A theoretical method based on the scattering K matrix has been used to calculate both the photoabsorption spectrum and the beta values, by taking both interference between direct and resonant photoemission and vibrational/lifetime interference into account. The numerical results show qualitative agreement with the trends detected in the experimental values and explain the conspicuous variations of the beta values primarily in terms of coupling between direct and resonant photoemission by interaction terms of different sign for different final vibrational states.
The Journal of Chemical Physics 02/2005; 122(8):84306. · 3.33 Impact Factor
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N. Saito,
A. DeFanis,
K. Kubozuka,
M. Machida,
M. Takahashi, H. Yoshida,
I. H. Suzuki,
A. Cassimi,
A. Czasch,
L. Schmidt,
R. Dörner,
K. Wang
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ABSTRACT: Measurements of photoelectron angular distributions for carbon K-shell ionization of fixed-in-space CO2 molecules with the molecular axis oriented along, perpendicular and at 45° to the electric vector of the light are reported. The major features of these measured spectra are fairly well reproduced by calculations employing a relaxed-core Hartree-Fock approach. In contrast to the angular distribution for K-shell ionization of N2, which exhibits a rich structure dominated by the f-wave (l = 3) at the shape resonance, the angular distribution for carbon K-shell photoionization of CO2 is quite unstructured over the entire observed range across the shape resonance.
Journal of Physics B-atomic Molecular and Optical Physics - J PHYS-B-AT MOL OPT PHYS. 01/2003; 36(1).
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ABSTRACT: A promotion of the O 1s electron in the CO2 molecule to the lowest unoccupied molecular orbital 2πu brings about the stretching and bending motions in the core-excited states. These nuclear motions are investigated by use of the sub-natural-width resonant Auger emission spectroscopy.
Chemical Physics Letters - CHEM PHYS LETT. 01/2000; 330(1):91-96.
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ABSTRACT: Deexcitation cross sections of Ne([sup 3][ital P][sub 2]), Ne([sup 3][ital P][sub 1]), and Ne([sup 3][ital P][sub 0]) by CH[sub 4], SiH[sub 4], GeH[sub 4], CF[sub 4], and SiF[sub 4] have been measured at a mean collisional energy corresponding to room temperature (295 K) and compared systematically with those by other molecules to understand general features of the cross section values dependent on both the electronic states of excited neon atoms and the target molecules. A small difference in the cross section values between metastable atoms, Ne([sup 3][ital P][sub 2]) and Ne([sup 3][ital P][sub 0]), and a resonant atom, Ne([sup 3][ital P][sub 1]), has indicated that Penning ionization by Ne([sup 3][ital P][sub 1]) is mainly governed by an electron exchange interaction rather than a dipole--dipole interaction. A spatial electron distribution of the outermost orbital of a target molecule is especially of great importance in the determination of the absolute cross section values in the deexcitation of excited neon atoms due to an electron exchange interaction.
Journal of Chemical Physics - J CHEM PHYS. 01/1993; 98(8):6190-6195.
