A theoretical spectroscopy study of theX3Σ−and theA3Π states of the C2S radical

Tarroni, Riccardo; Carter, Stuart; Handy, Nicholas C.

doi:10.1080/00268970701218704

Cited by 3 publications

(7 citation statements)

References 36 publications

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“…The 3 ⌸ 2 and 3 ⌸ 1 components of 3 are found to be 807 and 936 cm −1 above the A 3 ⌸ 2 ground state, respectively. These values are slightly larger than the 788 and 913 cm −1 calculated by Tarroni et al 9 The position of both 1 spin-orbit multiplets are in excellent agreement with the previous observations ͑see…”

Section: B Ccs −supporting

confidence: 93%

“…Peaks U and V are separated by 133 cm −1 and are assigned to the 3 ⌸ 2 and 3 ⌸ 1 spin-orbit components of the A 3 ⌸ state origin transition. This splitting is in excellent agreement with calculations by Tarroni et al 9 The 3 ⌸ 0 state is not observed because a photodetachment transition from a 2 ⌸ 3/2 anion state to a 3 ⌸ 0 neutral state requires a spin-flip which is nominally forbidden. The two remaining doublets are thus assigned to vibrations belonging to the same two spin-orbit states.…”

Section: B Ccs −supporting

confidence: 90%

“…3, most of the transitions to the X 3 ⌺ − state can be assigned based on the previous observations by LIF ͑Ref. 30͒ and recent calculations by Tarroni et al 9 Peaks B, D, and G are assigned to the 2 0 1 , 3 0 1 , and 1 0 1 transitions within the X 3 ⌺ − band, in agreement with the previous observations. 30 Peaks C and I are assigned to the 2 0 2 and 1 0 2 transitions, respectively.…”

Section: B Ccs −supporting

confidence: 89%

“…[3][4][5] CCS microwave absorption is used as a molecular probe of the velocity, density, and age of dark interstellar clouds 6,7 These species also serve as case studies for the theoretical treatment of spin-rovibronic interaction and vibronic coupling in linear triatomic molecules with triplet states. 8,9 The CCO and CCS radicals are known to have several low-lying singlet and triplet electronic states. While the X 3 ⌺ − ground state and the first optically accessible electronic state ͑A 3 ⌸͒ of these species have been studied in detail both experimentally and theoretically, less information is available on the singlet states.…”

Section: Introductionmentioning

confidence: 99%

“…Accordingly, most of the theoretical work on the CCO and CCS radicals has also focused on the structure of these two states as well as the Renner-Teller coupling in the upper state. 8,9,29,[31][32][33][34][35] Some calculations on the energetic and structures of the other low-lying electronic states have also been reported. 27,[36][37][38] The corresponding CCO − and CCS − anions have been the subject of a few experimental and theoretical investigations.…”

Section: Introductionmentioning

confidence: 99%

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Slow photoelectron imaging spectroscopy of CCO− and CCS−

Garand

Yacovitch

Neumark

2008

The Journal of Chemical Physics

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High-resolution photodetachment spectra of CCO(-) and CCS(-) using slow photoelectron velocity-map imaging spectroscopy are reported. Well-resolved transitions to the neutral X (3)Sigma(-), a (1)Delta, b (1)Sigma(+), and A (3)Pi states are seen for both species. The electron affinities of CCO and CCS are determined to be 2.3107+/-0.0006 and 2.7475+/-0.0006 eV, respectively, and precise term energies for the a (1)Delta, b (1)Sigma(+), and A (3)Pi excited states are also determined. The two low-lying singlet states of CCS are observed for the first time, as are several vibronic transitions within the four bands. Analysis of hot bands finds the spin-orbit orbit splitting in the X (2)Pi ground state of CCO(-) and CCS(-) to be 61 and 195 cm(-1), respectively.

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Section: B Ccs −supporting

confidence: 93%

Section: B Ccs −supporting

confidence: 90%

Section: B Ccs −supporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Slow photoelectron imaging spectroscopy of CCO− and CCS−

Garand

Yacovitch

Neumark

2008

The Journal of Chemical Physics

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Gas phase Elemental abundances in Molecular cloudS (GEMS)

Rocha,

Roncero,

Bulut

et al. 2023

A&A

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Context. Carbon monosulphide (CS) is among the few sulphur-bearing species that have been widely observed in all environments, including in the most extreme, such as diffuse clouds. Moreover, CS has been widely used as a tracer of the gas density in the interstellar medium in our Galaxy and external galaxies. Therefore, a complete understanding of its chemistry in all environments is of paramount importance for the study of interstellar matter. Aims. Our group is revising the rates of the main formation and destruction mechanisms of CS. In particular, we focus on those involving open-shell species for which the classical capture model might not be sufficiently accurate. In this paper, we revise the rates of reactions CH + S → CS + H and C2 + S → CS + C. These reactions are important CS formation routes in some environments such as dark and diffuse warm gas. Methods. We performed ab initio calculations to characterize the main features of all the electronic states correlating to the open shell reactants. For CH+S, we calculated the full potential energy surfaces (PESs) for the lowest doublet states and the reaction rate constant with a quasi-classical method. For C2+S, the reaction can only take place through the three lower triplet states, which all present deep insertion wells. A detailed study of the long-range interactions for these triplet states allowed us to apply a statistic adiabatic method to determine the rate constants. Results. Our detailed theoretical study of the CH + S → CS + H reaction shows that its rate is nearly independent of the temperature in a range of 10–500 K, with an almost constant value of 5.5 × 10−11 cm3 s−1 at temperatures above 100 K. This is a factor of about 2–3 lower than the value obtained with the capture model. The rate of the reaction C2 + S → CS + C does depend on the temperature, and takes values close to 2.0 × 10−10 cm3 s−1 at low temperatures, which increase to ~ 5.0 × 10−10 cm3 s−1 for temperatures higher than 200 K. In this case, our detailed modeling - taking into account the electronic and spin states – provides a rate that is higher than the one currently used by factor of approximately 2. Conclusions. These reactions were selected based on their inclusion of open-shell species with many degenerate electronic states, and, unexpectedly, the results obtained in the present detailed calculations provide values that differ by a factor of about 2–3 from the simpler classical capture method. We updated the sulphur network with these new rates and compare our results in the prototypical case of TMC1 (CP). We find a reasonable agreement between model predictions and observations with a sulphur depletion factor of 20 relative to the sulphur cosmic abundance. However, it is not possible to fit the abundances of all sulphur-bearing molecules better than a factor of 10 at the same chemical time.

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Vibronic coupling in the A2Π and B2Σ+ electronic states of the NCS radical

Tarroni

2011

The Journal of Chemical Physics

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The spin-rovibronic energy levels of the A(2)Π and B(2)Σ(+) electronic states of thiocyanate radical have been calculated variationally, using high-level ab initio coupled diabatic potential energy surfaces. Computations up to J = 7∕2 have been performed, obtaining all levels with K ≤ 3 (Σ(1/2),Π(1/2,3/2),Δ(3/2,5/2),Φ(5/2,7/2)), for energies up to 2000 cm(-1) above the A(000)(2)Π(3∕2) level. The available experimental data have been critically reviewed in the light of the theoretical findings.

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A theoretical spectroscopy study of theX³Σ⁻and theA³Π states of the C₂S radical

Cited by 3 publications

References 36 publications

Slow photoelectron imaging spectroscopy of CCO− and CCS−

Slow photoelectron imaging spectroscopy of CCO− and CCS−

Gas phase Elemental abundances in Molecular cloudS (GEMS)

Vibronic coupling in the A2Π and B2Σ+ electronic states of the NCS radical

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