|
1
|
Zagorodskikh S, Vapa M, Vahtras O, Zhaunerchyk V, Mucke M, Eland JHD, Squibb RJ, Linusson P, Jänkälä K, Ågren H, Feifel R. An experimental and theoretical study of core-valence double ionisation of acetaldehyde (ethanal). Phys Chem Chem Phys 2016; 18:2535-47. [PMID: 26700657 DOI: 10.1039/c5cp05758b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Core-valence double ionisation spectra of acetaldehyde (ethanal) are presented at photon energies above the carbon and oxygen 1s ionisation edges, measured by a versatile multi-electron coincidence spectroscopy technique. We use this molecule as a testbed for analyzing core-valence spectra by means of quantum chemical calculations of transition energies. These theoretical approaches range from two simple models, one based on orbital energies corrected by core valence interaction and one based on the equivalent core approximation, to a systematic series of quantum chemical electronic structure methods of increasing sophistication. The two simple models are found to provide a fast orbital interpretation of the spectra, in particular in the low energy parts, while the coverage of the full spectrum is best fulfilled by correlated models. CASPT2 is the most sophisticated model applied, but considering precision as well as computational costs, the single and double excitation configuration interaction model seems to provide the best option to analyze core-valence double hole spectra.
Collapse
Affiliation(s)
- S Zagorodskikh
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden and Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden.
| | - M Vapa
- Department of Theoretical Chemistry and Biology, School of Biotechnology, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden and Centre for Molecular Materials Research, University of Oulu, P.O. Box 3000, 90014 Oulu, Finland
| | - O Vahtras
- Department of Theoretical Chemistry and Biology, School of Biotechnology, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - V Zhaunerchyk
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden and Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden.
| | - M Mucke
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
| | - J H D Eland
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden and Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden.
| | - R J Squibb
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden and Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden.
| | - P Linusson
- Department of Physics, Stockholm University, AlbaNova University Center, SE-106 91 Stockholm, Sweden
| | - K Jänkälä
- Department of Physics, University of Oulu, 90014 Oulu, Finland
| | - H Ågren
- Department of Theoretical Chemistry and Biology, School of Biotechnology, KTH Royal Institute of Technology, SE-106 91 Stockholm, Sweden
| | - R Feifel
- Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden and Department of Physics, University of Gothenburg, Origovägen 6B, SE-412 96 Gothenburg, Sweden.
| |
Collapse
|
|
2
|
Kettunen JA, Niskanen J, Huttula M, Vapa M, Urpelainen S, Aksela H. Electron-ion coincidence study of photofragmentation of the CdCl(2) molecule. J Mass Spectrom 2011; 46:901-907. [PMID: 21915954 DOI: 10.1002/jms.1967] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
In this work, the photofragmentation subsequent to valence and Cd4d photoionization of cadmium dichloride (CdCl(2)) were studied using He I and synchrotron excitation. The measurements were performed with a photoelectron-photoion coincidence (PEPICO) setup, and the connection between the singly ionized electronic states and cationic fragments was investigated. The valence-ionized states were found to lead to CdCl(2)(+), Cd(+) and CdCl(+). The Cd4d(- 1) states were found to lead only to Cl(+) ions. The observed charge transfer effect between Cd and Cl was concluded to take place due to internal conversion or fluorescence decay to dissociating valence states either directly or through consecutive fragmentation. The fragmentation energetics were investigated with molecular ab initio calculations, and the calculated energies were found to agree with the detected fragment appearances.
Collapse
Affiliation(s)
- J A Kettunen
- Department of Physics, University of Oulu, P.O. Box 3000, FIN-90014, University of Oulu, Finland.
| | | | | | | | | | | |
Collapse
|