Investigation of valence orbitals of propene by electron momentum spectroscopy

Ning, Chuangang; Ren, Xueguang; Deng, Jiewei; Zhang, S. F.; Su, G.L.; Huang, Fan; Li, G. Q.

doi:10.1063/1.1926285

Cited by 10 publications

(2 citation statements)

References 22 publications

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“…The EMS binding energy spectra from the measurement were deconvoluted using a least-squares fit according to Bevington and Robinson 25 into Gaussians with fixed peak widths and positions but variable Gaussian heights (relative cross-sections). The procedure of extracting experimental MDs from those angular resolved energy spectra can be found in our previous work . In addition, the normalization of the measured orbital momentum distributions to the simulated in the theory is one of the general normalization methods used in the EMS field, employed by the Brion group at the University of British Columbia. , The procedure is to compare the experimental MDs with theoretical ones; the observed MDs were divided by a normalized constant to give a best fit.…”

Section: Methodsmentioning

confidence: 99%

New Diagnostic of the Most Populated Conformer of Tetrahydrofuran in the Gas Phase

Yang

Ning

et al. 2007

J. Phys. Chem. A

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The most populated conformer of tetrahydrofuran (C(4)H(8)O) has been diagnosed as the Cs conformer in the present study, jointly using experimental electron momentum spectroscopy (EMS) and quantum mechanics. Our B3LYP/6-311++G** model indicates that the C1 conformation, which is one of the three possible conformations of tetrahydrofuran produced by pseudorotation in the gas phase, is a transition state due to its imaginary frequencies, in agreement with the prediction from a recent ab initio MP2/aug-cc-pVTZ study (J. Chem. Phys. 2005, 122, 204303). The study has identified the fingerprint of the highest occupied molecular orbital (HOMO) of the C(s) (12a') conformer as the most populated conformer. The identification of the C(s) structure, therefore, leads to the orbital-based assignment of the ionization binding energy spectra of tetrahydrofuran for the first time, on the basis of the outer valence Green function OVGF/6-31G* model and the density functional theory (DFT) SAOP/ET-PVQZ model. The present study explores an innovative approach to study molecular stabilities. It also indicates that energetic properties are not always the most appropriate means to study conformer-rich biological systems.

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Section: Methodsmentioning

confidence: 99%

New Diagnostic of the Most Populated Conformer of Tetrahydrofuran in the Gas Phase

Yang

Ning

et al. 2007

J. Phys. Chem. A

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“…Electron momentum spectroscopy is known to be a powerful method for experimentally reconstructing valence orbital densities [16,17,[20][21][22][23][24][25]. Previous studies combining EMS experiments with theoretical modelling have shown that with this powerful spectroscopic technique, it is also possible to experimentally study the influence of the molecular conformation onto the spread, shape and topology of molecular orbitals [26][27][28][29][30][31][32].…”

Section: Introductionmentioning

confidence: 99%

Investigation of the molecular conformations of ethanol using electron momentum spectroscopy

Ning

Luo

Huang

et al. 2008

J. Phys. B: At. Mol. Opt. Phys.

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The valence electronic structure and momentum-space electron density distributions of ethanol have been investigated with our newly constructed high-resolution electron momentum spectrometer. The measurements are compared to thermally averaged simulations based on Kohn-Sham (B3LYP) orbital densities as well as one-particle Green's function calculations of ionization spectra and Dyson orbital densities, assuming Boltzmann's statistical distribution of the molecular structure over the two energy minima defining the anti and gauche conformers. One-electron ionization energies and momentum distributions in the outer-valence region were found to be highly dependent upon the molecular conformation. Calculated momentum distributions indeed very sensitively reflect the distortions and topological changes that molecular orbitals undergo due to the internal rotation of the hydroxyl group, and thereby exhibit variations which can be traced experimentally. The B3LYP model Kohn-Sham orbital densities are overall in good agreement with the experimental distributions, and closely resemble benchmark ADC(3) Dyson orbital densities. Both approaches fail to quantitatively reproduce the experimental momentum distributions characterizing the highest occupied molecular orbital. Since electron momentum spectroscopy measurements at various electron impact energies indicate that the plane wave impulse approximation is valid, this discrepancy between theory and experiment is tentatively ascribed to thermal disorder, i.e. large-amplitude and thermally induced dynamical distortions of the molecular structure in the gas phase.

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Progress on electron momentum spectroscopy studies at Tsinghua University in Beijing

Deng

Ning

Ren

et al. 2007

Journal of Electron Spectroscopy and Related Phenomena

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Investigation of valence orbitals of propene by electron momentum spectroscopy

Cited by 10 publications

References 22 publications

New Diagnostic of the Most Populated Conformer of Tetrahydrofuran in the Gas Phase

New Diagnostic of the Most Populated Conformer of Tetrahydrofuran in the Gas Phase

Investigation of the molecular conformations of ethanol using electron momentum spectroscopy

Progress on electron momentum spectroscopy studies at Tsinghua University in Beijing

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