Angular Dependence of Scattering Products in Electron-Molecule Resonant Excitation and in Dissociative Attachment

O'Malley, Thomas F.; Taylor, Howard S.

doi:10.1103/physrev.176.207

Cited by 210 publications

(77 citation statements)

References 12 publications

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“…15 The lack of agreement between our observed isotropy and the predicted angular dependencies 25 deserves further attention. These theoretical predictions agree with the rules derived by Dunn 35 for electron-impact processes and with the predictions of O'Malley and Taylor 36 for dissociative attachment. Dissociative attachment has distinct similarities with DR, but it lacks the long-range Coulomb attraction between the electron and the target.…”

supporting

confidence: 80%

Electron energy-dependent product state distributions in the dissociative recombination of O2+

Petrignani

Hellberg

Thomas

et al. 2005

The Journal of Chemical Physics

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We present product state distributions and quantum yields from the dissociative recombination reaction of O 2 + in its electronic and vibrational ground states as a function of electron collision energy between 0 and 300 meV. The experiments have been performed in the heavy-ion storage ring, CRYRING, and use a cold hollow-cathode discharge source for the production of cold molecular oxygen ions. The branching fractions over the different dissociation limits show distinct oscillations while the resulting product quantum yields are largely independent of electron collision energy above 40 meV. The branching results are well reproduced assuming an isotropic dissociation process, in contrast with recent theoretical predictions.

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supporting

confidence: 80%

Electron energy-dependent product state distributions in the dissociative recombination of O2+

Petrignani

Hellberg

Thomas

et al. 2005

The Journal of Chemical Physics

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“…Among the earliest work in this area is that of O'Malley [1,2] and O'Malley and Taylor [3] on dissociative attachment based on the idea of Feshbach partitioning of the electron scattering wave function into resonant and nonresonant parts. Herzenberg and coworkers [4][5][6] later applied these ideas to vibrational excitation and developed the local complex potential model that is generally known as the "boomerang model" in this context and that has been widely applied.…”

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confidence: 99%

Numerically solvable model for resonant collisions of electrons with diatomic molecules

2006

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We describe a simple model for electron-molecule collisions that has one nuclear and one electronic degree of freedom and that can be solved to arbitrarily high precision, without making the BornOppenheimer approximation, by employing a combination of the exterior complex scaling method and a finite-element implementation of the discrete variable representation. We compare exact cross sections for vibrational excitation and dissociative attachment with results obtained using the local complex potential approximation as commonly applied in the "boomerang" model, and suggest how this two-dimensional model can be used to test the underpinnings of contemporary nonlocal approximations to resonant collisions.

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“…We use the local complex potential or "boomerang" model [20][21][22][23][24] in which the nuclear motion is determined by a driven Schrodinger equation that describes the dynamics of the metastable H 2 O − electronic state(s) that correlate(s) with the neutral + anion fragments:…”

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confidence: 99%

Three-body breakup in dissociative electron attachment to the water molecule

2008

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We report the results of ab initio calculations on dissociative electron attachment (DEA) to water that demonstrate the importance of including three-body breakup in the dissociation dynamics. While three-body breakup is ubiquitous in the analogous process of dissociative recombination, its importance in low-energy dissociative electron attachment to a polyatomic target has not previously been quantified. Our calculations, along with our earlier studies of DEA into two-body channels, indicate that three-body breakup is a major component of the observed O − cross section. The local complex potential model provides a generally accurate picture of the experimentally observed features in this system, reproducing some quantitatively, others qualitatively, and one not at all.PACS numbers: 03.65. Nk, 34.80.Ht Dissociative electron attachment (DEA) to the water molecule, [9] observed the opening of the lower three-body channel, as discerned through the kinetic energy distribution of the O − fragment. However, because of the large O atom/H 2 mass ratio, such a measurement is difficult and a quantitative experimental determination of the final-state branching ratios among the two-and three-body breakup channels has yet to be published.There is strong reason to believe that three-body breakup is important for describing DEA leading to O − production. In particular, examination of the shape of the 2 A 1 surface suggests that three-body breakup may be the key to describing O − production via this resonance. The 2 A 1 (1 2 A ′ ) electronic surrface slopes downward toward linear H-O-H geometry and is dissociative along the OH bonds. It provides a path for symmetric dissociation of the OH bonds to produce O − + H + H, but also slopes downward toward the H − + OH asymptotes. Similarly, the 2 B 2 diabatic surface, which equals the 2 B 2 adiabatic surface for C 2v geometries, provides a path toward symmetric dissociation through the conical intersection with the 2 A 1 state. Symmetric dissociation of the 2 B 2 state from the equilibrium geometry of the neutral leads to the O − + H + H three-body asymptote.Our methodology is very similar to that used in our previous calculations, so we provide only a brief summary

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Angular Dependence of Scattering Products in Electron-Molecule Resonant Excitation and in Dissociative Attachment

Cited by 210 publications

References 12 publications

Electron energy-dependent product state distributions in the dissociative recombination of O2+

Electron energy-dependent product state distributions in the dissociative recombination of O2+

Numerically solvable model for resonant collisions of electrons with diatomic molecules

Three-body breakup in dissociative electron attachment to the water molecule

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