Abstract: Different computational methods are employed to evaluate elastic (rotationally summed) integral and differential cross sections for low energy (below about 10 eV) positron scattering off gas-phase C(2)H(2) molecules. The computations are carried out at the static and static-plus-polarization levels for describing the interaction forces and the correlation-polarization contributions are found to be an essential component for the correct description of low-energy cross section behavior. The local model potentials derived from density functional theory (DFT) and from the distributed positron model (DPM) are found to produce very high-quality agreement with existing measurements. On the other hand, the less satisfactory agreement between the R-matrix (RM) results and measured data shows the effects of the slow convergence rate of configuration-interaction (CI) expansion methods with respect to the size of the CI-expansion. To contrast the positron scattering findings, results for electron-C(2)H(2) integral and differential cross sections, calculated with both a DFT model potential and the R-matrix method, are compared and analysed around the shape resonance energy region and found to produce better internal agreement. (c) 2007 Elsevier B.V. All rights reserved.

Correlation–polarization effects in electron/positron scattering from acetylene: A comparison of computational models / J., Franz; Gianturco, Francesco Antonio; K. L., Baluja; J., Tennyson; R., Carey; R., Montuoro; R. R., Lucchese; T., Stoecklin; P., Nicholas; T. L., Gibson. - In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION B, BEAM INTERACTIONS WITH MATERIALS AND ATOMS. - ISSN 0168-583X. - STAMPA. - 266:(2008), pp. 425-434. (Intervento presentato al convegno 14th International Workshop on Low-Energy Positron and Positronium Physics tenutosi a Univ Reading, Reading, ENGLAND nel AUG 01-04, 2007) [10.1016/j.nimb.2007.12.019].

Correlation–polarization effects in electron/positron scattering from acetylene: A comparison of computational models

GIANTURCO, Francesco Antonio;
2008

Abstract

Abstract: Different computational methods are employed to evaluate elastic (rotationally summed) integral and differential cross sections for low energy (below about 10 eV) positron scattering off gas-phase C(2)H(2) molecules. The computations are carried out at the static and static-plus-polarization levels for describing the interaction forces and the correlation-polarization contributions are found to be an essential component for the correct description of low-energy cross section behavior. The local model potentials derived from density functional theory (DFT) and from the distributed positron model (DPM) are found to produce very high-quality agreement with existing measurements. On the other hand, the less satisfactory agreement between the R-matrix (RM) results and measured data shows the effects of the slow convergence rate of configuration-interaction (CI) expansion methods with respect to the size of the CI-expansion. To contrast the positron scattering findings, results for electron-C(2)H(2) integral and differential cross sections, calculated with both a DFT model potential and the R-matrix method, are compared and analysed around the shape resonance energy region and found to produce better internal agreement. (c) 2007 Elsevier B.V. All rights reserved.
2008
14th International Workshop on Low-Energy Positron and Positronium Physics
electron-molecule scattering; positron-molecule scattering; computed angular distributions for e(+)/e(-) scattering; quantum calculations; molecular gases
04 Pubblicazione in atti di convegno::04c Atto di convegno in rivista
Correlation–polarization effects in electron/positron scattering from acetylene: A comparison of computational models / J., Franz; Gianturco, Francesco Antonio; K. L., Baluja; J., Tennyson; R., Carey; R., Montuoro; R. R., Lucchese; T., Stoecklin; P., Nicholas; T. L., Gibson. - In: NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH. SECTION B, BEAM INTERACTIONS WITH MATERIALS AND ATOMS. - ISSN 0168-583X. - STAMPA. - 266:(2008), pp. 425-434. (Intervento presentato al convegno 14th International Workshop on Low-Energy Positron and Positronium Physics tenutosi a Univ Reading, Reading, ENGLAND nel AUG 01-04, 2007) [10.1016/j.nimb.2007.12.019].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/9965
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