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Engin S, González-Vázquez J, Maliyar GG, Milosavljević AR, Ono T, Nandi S, Iablonskyi D, Kooser K, Bozek JD, Decleva P, Kukk E, Ueda K, Martín F. Full-dimensional theoretical description of vibrationally resolved valence-shell photoionization of H 2O. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2019; 6:054101. [PMID: 31531387 PMCID: PMC6739208 DOI: 10.1063/1.5106431] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2019] [Accepted: 07/18/2019] [Indexed: 06/10/2023]
Abstract
We have performed a full-dimensional theoretical study of vibrationally resolved photoelectron emission from the valence shell of the water molecule by using an extension of the static-exchange density functional theory that accounts for ionization as well as for vibrational motion in the symmetric stretching, antisymmetric stretching, and bending modes. At variance with previous studies performed in centrosymmetric molecules, where vibrationally resolved spectra are mostly dominated by the symmetric stretching mode, in the present case, all three modes contribute to the calculated spectra, including intermode couplings. We have found that diffraction of the ejected electron by the various atomic centers is barely visible in the ratios between vibrationally resolved photoelectron spectra corresponding to different vibrational states of the remaining H2O+ cation (the so-called v-ratios), in contrast to the prominent oscillations observed in K-shell ionization of centrosymmetric molecules, including those that only contain hydrogen atoms around the central atoms, e.g., CH4. To validate the conclusions of our work, we have carried out synchrotron radiation experiments at the SOLEIL synchrotron and determined photoelectron spectra and v-ratios for H2O in a wide range of photon energies, from threshold up to 150 eV. The agreement with the theoretical predictions is good.
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Affiliation(s)
- Selma Engin
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | | | - Gianluigi Grimaldi Maliyar
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | | | - Taishi Ono
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | - Saikat Nandi
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
| | - Denys Iablonskyi
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
| | | | - John D Bozek
- Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, France
| | - Piero Decleva
- Dipartimento di Scienze Chimiche e Farmaceutiche, Universitá di Trieste and IOM-CNR, 34127 Trieste, Italy
| | - Edwin Kukk
- Department of Physics and Astronomy, University of Turku, 20014 Turku, Finland
| | - Kiyoshi Ueda
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan
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Jose J, Lucchese RR, Rescigno TN. Interchannel coupling effects in the valence photoionization of SF6. J Chem Phys 2015; 140:204305. [PMID: 24880278 DOI: 10.1063/1.4876576] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The complex Kohn and polyatomic Schwinger variational techniques have been employed to illustrate the interchannel coupling correlation effects in the valence photoionization dynamics of SF6. Partial photoionization cross sections and asymmetry parameters of six valence subshells (1t1g, 5t1u, 1t2u, 3eg, 1t2g, 4t1u) are discussed in the framework of several theoretical and experimental studies. The complex Kohn results are in rather good agreement with experimental results, indicative of the fact that the interchannel coupling effects alter the photoionization dynamics significantly. We find that the dominant effect of interchannel coupling is to reduce the magnitude of shape resonant cross sections near the threshold and to induce resonant features in other channels to which resonances are coupled. The long-standing issue concerning ordering of the valence orbitals is addressed and confirmed 4t1u (6)1t2g (6)3eg (4)(5t1u (6)+1t2u (6)) 1t1g (6) as the most likely ordering.
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Affiliation(s)
- J Jose
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - R R Lucchese
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, USA
| | - T N Rescigno
- Lawrence Berkeley National Laboratory, Chemical Sciences, Berkeley, California 94720, USA
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