Etude Expérimentale et Théorique de l'Iode Atomique. Observation du Spectre d'Arc Infrarouge, Classification et Structure Hyperfine

Luc‐Koenig, E.; Morillon, C.; Vergès, J.

doi:10.1088/0031-8949/12/4/004

Cited by 50 publications

(22 citation statements)

References 21 publications

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“…In addition, our excitation energy ( T 0 ) of O 2 ( a 1 Δ g ) of 7880 cm –1 is in excellent agreement with the experimental value of 7882 cm –1 , much better than the 8009 cm –1 value reported by Kaledin et al Our ZPE corrected exoergicity of R1 is 277 cm –1 , which is much closer to the experiment value (279 cm –1 ) than the 406 cm –1 value in earlier calculations . The calculated SO splitting for the iodine atom is 7209 cm –1 , which is close to the experimental data 7603 cm –1 . The discrepancy is presumably due to the more approximate theory used in such calculations.…”

supporting

confidence: 87%

Nonadiabatic Electronic Energy Transfer in the Chemical Oxygen–Iodine Laser: Powered by Derivative Coupling or Spin–Orbit Coupling?

Chen

et al. 2020

J. Phys. Chem. Lett.

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Derivative couplings near a conical intersection and spin–orbit couplings between different spin states are known to facilitate nonadiabatic transitions in molecular systems. Here, we investigate a prototypical electronic energy transfer process, I(2 P 3/2) + O2(a 1Δ g ) → I(2 P 1/2) + O2(X 3Σ g –), which is of great importance for the chemical oxygen–iodine laser. To understand the nonadiabatic dynamics, this multistate process is investigated in full dimensionality with quantum wave packets using diabatic potential energy surfaces coupled by both derivative and spin–orbit couplings, all determined from first principles. A near quantitative agreement with structural, energetic, and kinetic measurements is achieved. Detailed analyses suggest that the nonadiabatic dynamics is largely controlled by derivative coupling near conical intersections, which leads to a small effective barrier and hence a slightly positive temperature dependence of the rate coefficient. The new results should extend our understanding of energy transfer, provide a quantitative basis for numerical simulations of the chemical oxygen–iodine laser, and have important implications in other electronic energy transfer processes.

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supporting

confidence: 87%

Nonadiabatic Electronic Energy Transfer in the Chemical Oxygen–Iodine Laser: Powered by Derivative Coupling or Spin–Orbit Coupling?

Chen

et al. 2020

J. Phys. Chem. Lett.

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“…3 However, the 0.49 eV splitting, analogously determined for X = Br and dominated by SOC in the equatorialÃ + 2 A ′ state, is only half of the spin-orbit coupling in the iodine atom and significantly smaller than what was observed in iodomethane. 64,70 Additionally, the broadened and washed-out vibrational structure in the 2 P 1/2 spin-orbit band implies a short lifetime of the spin-orbit excited state.…”

Section: B Franck-condon Spectral Simulationsmentioning

confidence: 99%

Conformers, electronic states, and diabolical conical intersections in the valence photoelectron spectroscopy of halocyclohexanes

Zhou

Hemberger

et al. 2020

The Journal of Chemical Physics

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The threshold photoelectron spectrum (TPES) of halocyclohexanes C 6 H 11 X (X = Cl, Br, and I) was recorded at the Swiss Light Source and assigned with the help of density functional theory and equation-of-motion ionization potential coupled cluster calculations. Dyson orbitals show that the first two electronic states of the cation arise by symmetry breaking of the doubly degenerate eg orbitals in cyclohexane as perturbed by the halogen or by perturbation of the halogen lone pair by the cyclohexane ring scaffold in the case of light and heavy halogen substituents, respectively. When the resulting two states (A ′′ and A ′ ) are coupled via a conical intersection in C S symmetry, they are smoothly connected by molecular orbital rotation when the nuclear symmetry is relaxed. Even then, barriers at avoided crossings lead to distinct A ′ and pseudo-A ′′ minima, which contribute to the TPES separately. As axial and equatorial conformers are present in commensurate abundance at room temperature, four transitions are conceivable for each substituent in the low-energy range. Three of these could be identified, and their energy could be determined for each sample. Transitions to A ′ states are associated with a smaller geometry change and exhibit stronger origin transitions. Yet, most notably in X = Br, they do not correspond to the adiabatic ionization energy, which is indicated by a weak and broad band to the pseudo-A ′′ state with a lower onset energy. Franck-Condon vibrational analysis of the TPES coupled with quantum chemical calculations can provide insights into the behavior of conformers as well as strongly coupled electronic states.

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“…Only an 'ul' (upper limit) was assigned. Luc-Koenig, et al (1975). This determination is rated 'g' (good).…”

Section: Sample: Bromine (Br Z = 35)mentioning

confidence: 99%

“…The broken spectrum (blue online) was made with solar abundance. The full 12-component hyperfine structure was included fromLuc-Koenig, et al (1975). This determination is rated 'g' (good).…”

mentioning

confidence: 99%

A Study of the Elements Copper Through Uranium in Sirius A: Contributions From Stis and Ground-Based Spectra

Cowley

Ayres

Castelli

et al. 2016

ApJ

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We determine abundances or upper limits for all of the 55 stable elements from copper to uranium for the A1 Vm star Sirius. The purpose of the study is to assemble the most complete picture of elemental abundances with the hope of revealing the chemical history of the brightest star in the sky, apart from the Sun. We also explore the relationship of this hot metallic-line (Am) star to its cooler congeners, as well as the hotter, weakly-or non-magnetic mercury-manganese (HgMn) stars. Our primary observational material consists of Hubble Space Telescope (HST ) spectra taken with the Space Telescope Imaging Spectrograph (STIS) in the ASTRAL project. We have also used archival material from the COP ERN ICU S satellite, and from the HST Goddard High-Resolution Spectrograph (GHRS), as well as ground-based spectra from Furenlid, Westin, Kurucz, Wahlgren, and their coworkers, ESO spectra from the UVESPOP project, and NARVAL spectra retrieved from PolarBase. Our analysis has been primarily by spectral synthesis, and in this work we have had the great advantage of extensive atomic data unavailable to earlier workers. We find most abundances as well as upper limits range from 10 to 100 times above solar values. We see no indication of the huge abundance excesses of 1000 or more that occur among many chemically peculiar (CP) stars of the upper main sequence. The picture of Sirius as a hot Am star is reinforced.

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Etude Expérimentale et Théorique de l'Iode Atomique. Observation du Spectre d'Arc Infrarouge, Classification et Structure Hyperfine

Cited by 50 publications

References 21 publications

Nonadiabatic Electronic Energy Transfer in the Chemical Oxygen–Iodine Laser: Powered by Derivative Coupling or Spin–Orbit Coupling?

Nonadiabatic Electronic Energy Transfer in the Chemical Oxygen–Iodine Laser: Powered by Derivative Coupling or Spin–Orbit Coupling?

Conformers, electronic states, and diabolical conical intersections in the valence photoelectron spectroscopy of halocyclohexanes

A Study of the Elements Copper Through Uranium in Sirius A: Contributions From Stis and Ground-Based Spectra

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