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Please use this identifier to cite or link to this item: http://hdl.handle.net/1942/8529

Title: Benchmark Dyson orbital study of the ionization spectrum and electron momentum distributions of ethanol in conformational equilibrium
Authors: MORINI, Filippo
DELEUZE, Michael
Ning, Chuan G
Deng, Jing K
Issue Date: 2008
Citation: JOURNAL OF PHYSICAL CHEMISTRY A, 112(38). p. 9083-9096
Abstract: An extensive study, throughout the valence region, of the electronic structure, ionization spectrum, and electron momentum distributions of ethanol is presented, on the ground of a model that focuses on a mixture of the gauche and anti conformers in their energy minimum form, using weight coefficients obtained from thermostatistical calculations that account for the influence of hindered rotations. The analysis is based on accurate calculations of valence one-electron and shakeup ionization energies and of the related Dyson orbitals, using one-particle Green's Function (lp-GF) theory in conjunction with the so-called third-order Algebraic Diagrammatic Construction scheme [ADC(3)]. The confrontation against available UPS (HeI) measurements indicates the presence in the spectral bands of significant conformational fingerprints at outer-valence ionization energies ranging from similar to 14 to similar to 18 eV. The shakeup onset is located at similar to 24 eV, and a shoulder at similar to 14.5 eV in the He I spectrum can be specifically ascribed to the minor anti (C,) conformer fraction. Thermally and spherically averaged Dyson orbital momentum distributions are computed for seven resolvable bands in model (e, 2e) ionization spectra at an electron impact energy of 1.2 keV. A comparison is made with results obtained from standard (B3LYP) Kohn-Sham orbitals and EMS measurements employing a high-resolution spectrometer of the third generation. The analysis is qualitatively in line with experiment and reveals a tremendously strong influence of the molecular conformation on the outermost electron momentum distributions. Quantitatively significant discrepancies with experiment can nonetheless be tentatively ascribed to strong dynamical disorder in the gas phase molecular structure.
Notes: Hasselt Univ, Res Grp Theoret Chem, Dept SBG, B-3590 Diepenbeek, Belgium. Tsinghua Univ, Dept Phys, Beijing 100084, Peoples R China. Tsinghua Univ, Key Lab Atom & Mol NanoSci MOE, Beijing 100084, Peoples R China.
URI: http://hdl.handle.net/1942/8529
DOI: 10.1021/jp804284p
ISI #: 000259341900027
ISSN: 1089-5639
Category: A1
Type: Journal Contribution
Validation: ecoom, 2009
Appears in Collections: Research publications

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