Abstract We present a comprehensive electron momentum spectroscopy study on the electronic structure of trifluorobromomethane. The binding energy spectrum and profiles entire outer-valence orbitals first inner-valence orbital along with several shake-up states were measured by using high-sensitivity (e, 2e) apparatus at an impact 1213 eV. Theoretical calculations employing density functional theory B3LYP hybrid symmetry-adapted cluster configuration-interaction method performed to interpret...

We report nonsequential and sequential fragmentation dynamics of ${{\mathrm{CO}}_{2}}^{3+}$ investigated by electron collision at an impact energy 500 eV. The dissociation mechanisms are clearly distinguished combined use the Dalitz plot together with momentum correlation spectra. angular distributions kinetic-energy releases (KERs) different processes obtained. channels higher excited states molecular ion opened, which quite from previous studies heavy-ion [N. Neumann, D. Hant, L. Ph. H....

If a molecular dication is produced on repulsive potential energy surface (PES), it normally dissociates. Before that, however, ultrafast nuclear dynamics can change the PES and significantly influence fragmentation pathway. Here, we investigate electron-impact-induced double ionization subsequent processes of ethanol molecule using multiparticle coincident momentum spectroscopy ab initio dynamical simulations. For electronic ground state dication, observe several channels that cannot be...

The fragmentation dynamics of OCSq+ (q = 2, 3, 4) induced by electron collision at an impact energy 500 eV is studied. By using the momentum imaging technique, three dimensional vectors all fragments are obtained, which enables us to analyse both kinetic release and correlations for a certain channel. Up fifteen dissociation channels analyzed including six, five, four two-body, incomplete complete three-body Coulomb fragmentations. For dissociation, mechanisms investigated with help Dalitz...

The valence-shell electron momentum distributions for 1-butene are measured by spectroscopy (EMS) employing non-coplanar symmetric geometry. experimental compared with the density functional theory (DFT) calculations using different-sized basis sets. Although two conformers of in gas phase, namely skew and syn, have very close ionization potentials, distributions, especially low region, can show prominent differences some valence orbitals. By comparing profiles theoretical ones, conformer is...

A high-sensitivity angle and energy dispersive multichannel electron momentum spectrometer with simultaneous detection in 2π range is presented. newly designed double half wedge strip anode position-sensitive detector employed to collect the ionized scattered electrons passing through a 90° sector, spherical electrostatic analyzer over azimuthal of about 150° for each. Experimental results on argon are presented exhibit performance spectrometer.

Vibrational effects on electron momentum distributions (EMDs) of outer-valence orbitals oxetane are computed with a comprehensive consideration all vibrational modes. It is found that motions influence EMDs noticeably. The agreement between theoretical and experimental profiles the first five greatly improved when including molecular vibrations in calculation. In particular, large turn-up at low profile 3b1 orbital well interpreted by effects, indicating that, besides low-frequency...

The interpretation of experimental electron momentum distributions (EMDs) ethanol, one the simplest molecules having conformers, has confused researchers for years. High-level calculations Dyson orbital EMDs by thermally averaging gauche and trans conformers as well molecular dynamical simulations failed to quantitatively reproduce experiments some outer valence orbitals. In this work, shell binding energy spectrum ethanol are revisited high-sensitivity spectrometer employing symmetric...

The three-body fragmentation dynamics of cyclopropane $({\text{C}}_{3}{\text{H}}_{6})$ induced by ${\text{Ni}}^{19+}$ ions at an impact energy 5.8 MeV/u are studied using a cold target recoil ion momentum spectroscopy (COLTRIMS) reaction microscope. Two completely measured channels ${\text{C}}_{3}{\text{H}}_{6}^{3+}$ were identified definitely, i.e., ${\text{C}}_{3}{\text{H}}_{6}^{3+}\ensuremath{\rightarrow}{\text{H}}^{+}+\text{C}{\text{H}}_{2}^{+}+{\text{C}}_{2}{\text{H}}_{3}^{+}$ and...

The binding energy spectra of cyclopropane in range 9–19 eV have been measured by the high resolution (e, 2e) spectrometer with 0.5 resolution. individual electron momentum distributions for outer valence orbitals including two Jahn–Teller splitting components highest occupied molecular orbital 3e′ obtained. Compared results level quantum chemistry calculations, observed different intensities experimental profiles phenomenologically explained, showing influences caused change geometry at...

We report the first measurement on vibrationally resolved electron momentum spectroscopy of H2 by using a high-resolution (e, 2e) spectrometer. The vibrational-specific experimental profiles have been obtained and shown to be in agreement with calculations ionization cross sections taking into account vibrational wave functions. Distinct deviations from Franck-Condon predictions observed ratios sections, which can readily ascribed Young-type two-center interference. Unlike previous work,...

On account of controversial orbital assignment that appeared in previous works, [J. Chem. Phys. 120, 7933 (2004), and references therein] high resolution electron momentum spectroscopy (EMS) measurements on dichlorodifluoromethane has been carried out using a newly developed energy-momentum dispersive multichannel spectrometer employing asymmetric noncoplanar geometry at an impact energy 2500eV plus binding energy. Four resolved structures two shoulders were obviously observed spectrum range...

The extensive study of outer- and inner-valence satellites carbon dioxide by electron momentum spectroscopy is reported. experiments have been performed using a high-sensitivity spectrometer employing non-coplanar symmetric geometry at impact energy about 1200 eV. Binding spectrum up to 50 eV, above the first double ionization threshold (~37.3 eV), presented. Four main peaks twelve identified including four embedded in continuum, among which two beyond 42 eV are observed for time. High...

A momentum imaging spectrometer has been built for studying the electron impact molecular fragmentation dynamics. The setup consists of a pulsed gun and time flight system as well two-dimensional position sensitive multi-hit detector. charged fragments with kinetic energy up to 10 eV can be detected in 4π solid angles their three-dimensional vectors reconstructed. apparatus is tested by ionization Ar dissociative CO2. By analyzing ion-ion coincidence spectra, complete incomplete Coulomb...

The binding energy spectra and electron momentum distributions for the outer-valence molecular orbitals of oxetane have been measured utilizing (e, 2e) spectrometer with non-coplanar asymmetric geometry at impact 2500 eV. experimental were compared density functional theory calculations employing B3LYP hybrid aug-cc-pVTZ basis set. It was found that calculation planar (C2v) completely fails to interpret large "turn-up" low region in distribution highest occupied orbital (HOMO) 3b1, while...

The valence-shell binding energy spectra and electron momentum profiles of gaseous ethylamine are measured by (e, 2e) spectroscopy. When taking into account the Boltzmann-weighted abundance 39% for trans 61% two equivalent gauche conformers coexisted in ethylamine, thermally averaged all valence orbitals calculated using B3LYP method with 6-311++G** aug-cc-pVTZ basis sets reproduce experimental ones well, which supports that conformer is more stable. In addition, controversial ordering 2a′′...

Fragmentation of ${\text{CO}}_{2}{}^{4+}$ induced by electron impact at the energy 500 eV is studied using a momentum imaging spectrometer. It found that decays mainly through two three-body-fragmentation channels: ${\mathrm{CO}}_{2}{}^{4+}\ensuremath{\rightarrow}{\mathrm{O}}^{+}+{\mathrm{C}}^{2+}+{\mathrm{O}}^{+}$ (121) and ${\mathrm{CO}}_{2}{}^{4+}\ensuremath{\rightarrow}{\mathrm{O}}^{2+}+{\mathrm{C}}^{+}+{\mathrm{O}}^{+}$ (211). The fragmentation dynamics these channels are analyzed...

We report experimental investigations of two-body fragmentation ${\mathrm{C}}_{2}{{\mathrm{H}}_{2}}^{2+}$ induced by 1 keV electron collision utilizing an ion momentum imaging spectrometer. With the ion-ion coincidence measurement, dissociation channels ${\mathrm{C}}_{2}{{\mathrm{H}}_{2}}^{2+}\ensuremath{\rightarrow}{\mathrm{H}}^{+}+{\mathrm{C}}_{2}{\mathrm{H}}^{+}$ (deprotonation) and...

Two-dimensional electron density map (2D map) of binding energy and relative azimuthal angle (i.e., momentum) for the outer-valence molecular orbitals SF6 has been measured by a highly sensitive momentum spectrometer with noncoplanar symmetric geometry at impact 1.2 keV plus energy. The experimental profiles relevant have extracted from 2D interpreted on basis quantitative calculations using functional theory B3LYP hybrid functional. For outermost F2p nonbonding SF6, interference patterns...

The binding energy spectra and electron momentum distributions for the outer-valence molecular orbitals of gaseous cyclopropylamine (CPA) have been measured by (e, 2e) spectrometer employing noncoplanar asymmetric geometry at impact 2500 eV. experimental results are interpreted on basis quantitative calculations ionization energies relevant benchmark theoretical levels using Green's function method, symmetry-adapted cluster configuration interaction density functional theory with B3LYP...

We report an investigation on the fragmentation dynamics of SO2q+ (q = 2-4) induced by 1 keV electron collision utilizing ion momentum imaging spectrometer. Six complete Coulomb explosion channels were observed using time-of-flight correlation map. The kinetic energy release distributions for these obtained and compared with those available in literature. mechanisms three-body dissociation analyzed Dalitz plots Newton diagrams. Both concerted breakup sequential pathways identified channel...

The binding energy spectra and electron momentum distributions for the complete valence orbitals of ethanethiol were measured first time by binary (e, 2e) spectroscopy employing non-coplanar symmetric kinematics at an impact 1200 eV plus energy. experimental results are generally consistent with theoretical calculations using density functional theory HartreeFock methods various basis sets. A possible satellite line 17.8 in spectrum was observed studied spectroscopy.