Vibrational structure in electron scattering by O2

Gray, R. L.; Haselton, H.H.; Krause, Daniel; Soltysik, Edward A.

doi:10.1016/0009-2614(72)80040-x

Cited by 9 publications

(4 citation statements)

References 3 publications

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“…For ClF + , Huber and Herzberg reference DeKock et al who report a vibrational frequency of 870 ± 30 cm –1 , while Anderson et al report a frequency of 912 ± 30 cm –1 . Our calculations, which predict a ClF + frequency of 917 cm –1 , more closely agree with the work of Anderson et al Similarly, for O 2 – , Huber and Herzberg cite a value of 1090 cm –1 based on the works of Boness and Schulz and Linder and Schmidt while also noting that Gray et al and Creighton and Lippincott give values of 1140 and 1145 cm –1 , respectively. In a more recent study, Ervin et al give a value of 1108 ± 20 cm –1 , which is in good agreement with our theoretical predictions of 1117 cm –1 .…”

Section: Resultssupporting

confidence: 90%

Polishing the Gold Standard: The Role of Orbital Choice in CCSD(T) Vibrational Frequency Prediction

Bertels

Head‐Gordon

2021

J. Chem. Theory Comput.

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While CCSD(T) with spin-restricted Hartree−Fock (RHF) orbitals has long been lauded for its ability to accurately describe closed-shell interactions, the performance of CCSD(T) on open-shell species is much more erratic, especially when using a spin-unrestricted HF (UHF) reference. Previous studies have shown improved treatment of open-shell systems when a non-HF set of molecular orbitals, like Brueckner or Kohn−Sham density functional theory (DFT) orbitals, is used as a reference. Inspired by the success of regularized orbitaloptimized second-order Møller−Plesset perturbation theory (κ-OOMP2) orbitals as reference orbitals for MP3, we investigate the use of κ-OOMP2 orbitals and various DFT orbitals as reference orbitals for CCSD(T) calculations of the corrected ground-state harmonic vibrational frequencies of a set of 36 closed-shell (29 neutrals, 6 cations, 1 anion) and 59 open-shell diatomic species (38 neutrals, 15 cations, 6 anions). The aug-cc-pwCVTZ basis set is used for all calculations. The use of κ-OOMP2 orbitals in this context alleviates difficult cases observed for both UHF orbitals and OOMP2 orbitals. Removing two multireference systems and 12 systems with ambiguous experimental data leaves a pruned data set. Overall performance on the pruned data set highlights CCSD(T) with a B97 orbital reference (CCSD(T):B97), CCSD(T) with a κ-OOMP2 orbital reference (CCSD(T):κ-OOMP2), and CCSD(T) with a B97M-rV orbital reference (CCSD(T):B97M-rV) with RMSDs of 8.48 cm −1 , and 8.50 cm −1 , and 8.75 cm −1 respectively, outperforming CCSD(T):UHF by nearly a factor of 5. Moreover, the performance on the closed-and openshell subsets shows these methods are able to treat open-shell and closed-shell systems with comparable accuracy and robustness. CCSD(T) with RHF orbitals is seen to improve upon UHF for the closed-shell species, while spatial symmetry breaking in a number of restricted open-shell HF (ROHF) references leads CCSD(T) with ROHF reference orbitals to exhibit the poorest statistical performance of all methods surveyed for open-shell species. The use of κ-OOMP2 orbitals has also proven useful in diagnosing multireference character that can hinder the reliability of CCSD(T).

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Section: Resultssupporting

confidence: 90%

Polishing the Gold Standard: The Role of Orbital Choice in CCSD(T) Vibrational Frequency Prediction

Bertels

Head‐Gordon

2021

J. Chem. Theory Comput.

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“…Here, we present vibrational and spin-orbit state-resolved ultraviolet photoelectron spectra and high-level ab initio quantum mechanical calculations that show unequivocally that these assignments [41][42][43] of a high electron affinity and of multiple adiabati-cally electronically bound O 2excited states are incorrect. Our resultsmaybecomparedwithpreviousphotoelectronspectroscopy [11][12][13][14][15][16][17][18][19][20] and electron scattering 21,22,[36][37][38][44][45][46][47][48][49] experiments and theoretical calculations. 40,[50][51][52][53][54][55][56][57] Photoelectron Spectroscopy of O 2 -.…”

Section: Introductionmentioning

confidence: 83%

“…Vibrational states of O 2up to V′′ ) 3 have been observed as hot bands in photoelectron spectra, 11,19,20 while higher vibrational states, V′′ g 4, are above the detachment limit and have been observed as resonances in low-energy electron scattering on O 2 . 22,[44][45][46][47][48][49] The hot bands are further identified by their different intensities relative to the origin in previously published photoelectron spectra with different O 2vibrational temperatures. For example, intense V′′ ) 1, 2, and 3 hot bands at eBE ≈ 0.31, 0.18, and 0.05 eV, respectively, are observed from a hot cesium-ion sputtering source, 11 while they are absent from a cold pulsedbeam supersonic jet source.…”

Section: Introductionmentioning

confidence: 99%

The Only Stable State of O₂^-Is the X²Π_gGround State and It (Still!) Has an Adiabatic Electron Detachment Energy of 0.45 eV

et al. 2003

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The ultraviolet photoelectron spectrum of O 2 -exhibits 29 resolved vibronic transitions to the three low-lying electronic states of neutral O 2 (X 3 Σ g -, a 1 ∆g, b 1 Σ g + ) from the X 2 Π J (J ) 3/2 and 1/2) spin-orbit states of the anion. A Franck-Condon simulation, using the established molecular constants of the neutral oxygen states, matches every observed feature in the spectrum. The 0-0 origin transition is unambiguously assigned, yielding the electron affinity EA 0 (O 2 ) ) 0.448 ( 0.006 eV. The derived bond dissociation energy is D 0 (O 2 -) ) 395.9 ( 0.6 kJ/mol. Coupled-cluster theory at the CCSD(T)/aug-cc-pVTZ level is used to determine the potential energy curves of O 2 and of O 2 -in its ground state and two excited states, in both the electronically bound and unbound regions. Stabilization methods are employed to characterize the anion curves at bond lengths where their electronic energies lie above that of the ground-state neutral. The calculations confirm that the O 2 -X 2 Π g ground state is adiabatically stable, but the lowest electronically excited states of O 2 -(a 4 Σ u -and A 2 Π u ) are adiabatically unbound with respect to electron detachment. The calculations predict the anionic doublet-quartet splitting to be T e (a 4 Σ u -) -T e (X 2 Π g ) ) 2.40 eV and the first excited doublet at an energy of T e (A 2 Π u ) -T e (X 2 Π g ) ) 3.39 eV. These observations are consistent with electron scattering on O 2 and other experimental data, and they sharply refute recent interpretations of electron-capture detector experiments that EA(O 2 ) ≈ 1 eV, that O 2 -has multiple excited states below the neutral ground-state minimum, and that the doublet-quartet splitting is 0.12 eV [Chen, E. S.; Chen, E. C. M.

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“…The experimental vibrational constants used in the Dunham expansion for this ion are the ones reported from the most recent spectroscopic measurement [8]. Other vibrational constants were also proposed for this ion in the literature, for example x e = 1090 cm À1 and x e x e = 8 cm À1 [2,3], as well as x e = 1140 cm À1 and x e x e = 12 cm À1 [40] can be found in earlier works.…”

Section: Eigenstatesmentioning

confidence: 95%

Electrochemical reduction of the O2 molecule to the radical ion – A theoretical approach

Ignaczak

Schmickler

Bartenschlager

2006

Journal of Electroanalytical Chemistry

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Vibrational structure in electron scattering by O2

Cited by 9 publications

References 3 publications

Polishing the Gold Standard: The Role of Orbital Choice in CCSD(T) Vibrational Frequency Prediction

Polishing the Gold Standard: The Role of Orbital Choice in CCSD(T) Vibrational Frequency Prediction

The Only Stable State of O₂^-Is the X²Π_gGround State and It (Still!) Has an Adiabatic Electron Detachment Energy of 0.45 eV

Electrochemical reduction of the O2 molecule to the radical ion – A theoretical approach

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Vibrational structure in electron scattering by O2

Cited by 9 publications

References 3 publications

Polishing the Gold Standard: The Role of Orbital Choice in CCSD(T) Vibrational Frequency Prediction

Polishing the Gold Standard: The Role of Orbital Choice in CCSD(T) Vibrational Frequency Prediction

The Only Stable State of O2-Is the X2ΠgGround State and It (Still!) Has an Adiabatic Electron Detachment Energy of 0.45 eV

Electrochemical reduction of the O2 molecule to the radical ion – A theoretical approach

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The Only Stable State of O₂^-Is the X²Π_gGround State and It (Still!) Has an Adiabatic Electron Detachment Energy of 0.45 eV