1
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Álvarez L, Bass AD, Lozano AI, García-Abenza A, Limão-Vieira P, Sanche L, García G. Electron stimulated desorption from condensed benzene. Phys Chem Chem Phys 2024; 26:9197-9206. [PMID: 38376884 DOI: 10.1039/d3cp06289a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2024]
Abstract
The electron induced dissociation of condensed benzene (C6H6) in thin films deposited on a Pt substrate is investigated by electron stimulated desorption (ESD) of anions and cations. The desorbed yields are recorded as a function of incident electron energy in the range of 10 to 950 eV for a fixed film thickness of 2 monolayers (ML) and for a fixed energy of 950 eV, as well as a function of film thickness from 0.5 to 8 monolayers (ML) for anions, and from 0.5 to 12ML for cations. Both energy and thickness dependencies are discussed in terms of the three main mechanisms yielding positively and/or negatively charged fragments: dissociative electron attachment (DEA), dipolar dissociation (DD) and dissociative ionization (DI) processes. At the probed energies, DD is the major mechanism, while DEA is predominantly induced by secondary electrons from the Pt substrate. Desorption of the parent positive ion is strongly suppressed. Similar qualitative behaviours are observed for the energy dependence of both anion and cation ESD yields, while some discrepancies exist in the thickness dependence, including a very significant systematic magnitude difference found between such ions formation. An estimation of the effective DD cross-section including the desorption probability is obtained. Feasible mechanisms behind the observed energy and thickness dependences for anion and cation yields are proposed. These results highlight the need for further investigations to better understand the underlying processes of electron induced dissociation in condensed matter.
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Affiliation(s)
- L Álvarez
- Fundamental Physics Institute, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, Madrid 28006, Spain.
| | - A D Bass
- Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Québec, Canada
| | - A I Lozano
- Fundamental Physics Institute, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, Madrid 28006, Spain.
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica 2829-516, Portugal
- Institut de Recherche en Astrophysique et Planétologie (IRAP), Université Toulouse III - Paul Sabatier, 9 Avenue du Colonel Roche, Toulouse 31028, France
| | - A García-Abenza
- Fundamental Physics Institute, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, Madrid 28006, Spain.
- Spanish Meteorological Agency (AEMET), Murcia, Spain
| | - P Limão-Vieira
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Caparica 2829-516, Portugal
| | - L Sanche
- Department of Nuclear Medicine and Radiobiology, Faculty of Medicine and Health Sciences, University of Sherbrooke, Québec, Canada
| | - G García
- Fundamental Physics Institute, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, Madrid 28006, Spain.
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia
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2
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Dalagnol LVS, Moreira GM, Souza Barbosa A, Bettega MHF. Low-Energy Electron and Positron Scattering by para-Difluorobenzene. J Phys Chem A 2023; 127:6486-6494. [PMID: 37526615 DOI: 10.1021/acs.jpca.3c03802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023]
Abstract
The Schwinger multichannel method is employed in calculations of the elastic integral and differential cross sections for collisions of low-energy electrons and positrons with para-difluorobenzene (1,4-C6H4F2). The present calculations involving electron scattering have been performed using both static-exchange and static-exchange plus polarization levels of approximation. Our results indicate the presence of three resonances of π*-character in the low-energy region and a fourth resonance, of σ*-character, at higher energy levels. With respect to the positron scattering, the calculations were conducted using the static plus polarization approximation at three different polarization levels. The present calculated electron and positron cross sections show a reasonable agreement with the total cross sections measured by Makochekanwa et al. (J. Phys. B, 2004, 37, 1841). It is also important to highlight that our computed integral cross section for electron scattering indicates the presence of a Ramsauer-Townsend minimum, while the integral cross section for positron scattering indicates the presence of a virtual state.
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Affiliation(s)
- Luiz V S Dalagnol
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
| | - Giseli M Moreira
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
| | - Alessandra Souza Barbosa
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
| | - Márcio H F Bettega
- Departamento de Física, Universidade Federal do Paraná, Caixa Postal 19044, 81531-980 Curitiba, Paraná, Brazil
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3
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García-Abenza A, Lozano AI, Álvarez L, Oller JC, Rosado J, Blanco F, Limão-Vieira P, García G. Evaluated electron scattering cross section dataset for gaseous benzene in the energy range 0.1-1000 eV. Phys Chem Chem Phys 2023. [PMID: 37470102 DOI: 10.1039/d3cp01908j] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
In this study, a complete and self-consistent cross section dataset for electron transport simulations through gaseous benzene in the energy range 0.1-1000 eV has been critically compiled. Its reliability has been evaluated through a joint experimental and computational procedure. To accomplish this, the compiled dataset has been used as input for event-by-event Monte Carlo simulations of the magnetically confined electron transport through gaseous benzene, and the simulated transmitted intensity has been compared with the experimental one for different incident energies and benzene gas pressures.
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Affiliation(s)
- A García-Abenza
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain.
| | - A I Lozano
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain.
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
| | - L Álvarez
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain.
| | - J C Oller
- Centro de Investigaciones Energéticas Mediambientales y Tecnológicas - CIEMAT, 28040 Madrid, Spain
| | - J Rosado
- Departamento de Estructura de la Materia, Física Térmica y Electrónica e IPARCOS, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - F Blanco
- Departamento de Estructura de la Materia, Física Térmica y Electrónica e IPARCOS, Universidad Complutense de Madrid, 28040 Madrid, Spain
| | - P Limão-Vieira
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
| | - G García
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain.
- Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia
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4
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Lozano AI, García-Abenza A, Blanco Ramos F, Hasan M, Slaughter DS, Weber T, McEachran RP, White RD, Brunger MJ, Limão-Vieira P, García Gómez-Tejedor G. Electron and Positron Scattering Cross Sections from CO 2: A Comparative Study over a Broad Energy Range (0.1-5000 eV). J Phys Chem A 2022; 126:6032-6046. [PMID: 36069053 PMCID: PMC9483986 DOI: 10.1021/acs.jpca.2c05005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
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In this Review, we present a comparative study between
electron
and positron scattering cross sections from CO2 molecules
over a broad impact energy range (0.1–5000 eV). For electron
scattering, new total electron scattering cross sections (e-TCS) have
been measured with a high resolution magnetically confined electron
beam transmission system from 1 to 200 eV. Dissociative electron attachment
processes for electron energies from 3 to 52 eV have been analyzed
by measuring the relative O– anion production yield.
In addition, elastic, inelastic, and total scattering cross section
calculations have been carried out in the framework of the Independent
Atom Model by using the Screening Corrected Additive Rule, including
interference effects (IAM-SCARI). Based on the previous cross section
compilation from Itikawa (J. Phys. Chem. Ref. Data, 2002, 31, 749−767) and the
present measurements and calculations, an updated recommended e-TCS
data set has been used as reference values to obtain a self-consistent
integral cross section data set for the elastic and inelastic (vibrational
excitation, electronic excitation, and ionization) scattering channels.
A similar calculation has been carried out for positrons, which shows
important differences between the electron scattering behavior: e.g.,
more relevance of the target polarization at the lower energies, more
efficient excitation of the target at intermediate energies, but a
lower total scattering cross section for increasing energies, even
at 5000 eV. This result does not agree with the charge independence
of the scattering cross section predicted by the first Born approximation
(FBA). However, we have shown that the inelastic channels follow the
FBA’s predictions for energies above 500 eV while the elastic
part, due to the different signs of the scattering potential constituent
terms, remains lower for positrons even at the maximum impact energy
considered here (5000 eV). As in the case of electrons, a self-consistent
set of integral positron scattering cross sections, including elastic
and inelastic (vibrational excitation, electronic excitation, positronium
formation, and ionization) channels is provided. Again, to derive
these data, positron scattering total cross sections based on a previous
compilation from Brunger et al. (J. Phys. Chem. Ref. Data, 2017, 46, 023102) and the present calculation
have been used as reference values. Data for the main inelastic channels,
i.e. direct ionization and positronium formation, derived with this
procedure, show excellent agreement with the experimental results
available in the literature. Inconsistencies found between different
model potential calculations, both for the elastic and inelastic collision
processes, suggest that new calculations using more sophisticated
methods are required.
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Affiliation(s)
- Ana I Lozano
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain.,Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Adrián García-Abenza
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain
| | - Francisco Blanco Ramos
- Departamento de Estructura de la Materia, Física Térmica y Electrónica e IPARCOS, Universidad Complutense de Madrid, Avenida Complutense, E-28040 Madrid, Spain
| | - Mahmudul Hasan
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States
| | - Daniel S Slaughter
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Thorsten Weber
- Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Robert P McEachran
- The Research School of Physics, Australian National University, Canberra, ACT 0200, Australia
| | - Ronald D White
- College of Science and Engineering, James Cook University, Townsville 4810, Australia
| | - Michael J Brunger
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia.,Department of Actuarial Science and Applied Statistics, Faculty of Business and Management, UCSI University, Kuala Lumpur 56000, Malaysia
| | - Paulo Limão-Vieira
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - Gustavo García Gómez-Tejedor
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain.,Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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5
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Guerra C, Kumar S, Aguilar-Galindo F, Díaz-Tendero S, Lozano AI, Mendes M, Oller JC, Limão-Vieira P, García G. Total Electron Detachment and Induced Cationic Fragmentation Cross Sections for Superoxide Anion (O 2-) Collisions with Benzene (C 6H 6) Molecules. Int J Mol Sci 2022; 23:ijms23031266. [PMID: 35163189 PMCID: PMC8835784 DOI: 10.3390/ijms23031266] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 01/17/2022] [Accepted: 01/21/2022] [Indexed: 02/06/2023] Open
Abstract
In this study, novel experimental total electron detachment cross sections for O2- collisions with benzene molecules are reported for the impact energy range (10-1000 eV), as measured with a transmission beam apparatus. By analysing the positively charged species produced during the collision events, relative total ionisation cross sections were derived in the incident energy range of 160-900 eV. Relative partial ionisation cross sections for fragments with m/z ≤ 78 u were also given in this energy range. We also confirmed that heavier compounds (m/z > 78 u) formed for impact energies between 550 and 800 eV. In order to further our knowledge about the collision dynamics governing the fragmentation of such heavier molecular compounds, we performed molecular dynamics calculations within the framework of the Density Functional Theory (DFT). These results demonstrated that the fragmentation of these heavier compounds strongly supports the experimental evidence of m/z = 39-42, 50, 60 (u) cations formation, which contributed to the broad local maximum in the total ionisation observed from 550 to 800 eV. This work reveals the reactivity induced by molecular anions colliding with hydrocarbons at high energies, processes that can take place in the interstellar medium under various local conditions.
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Affiliation(s)
- Carlos Guerra
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain;
| | - Sarvesh Kumar
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (S.K.); (A.I.L.); (M.M.); (P.L.-V.)
| | - Fernando Aguilar-Galindo
- Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain;
| | - Sergio Díaz-Tendero
- Departamento de Química, Módulo 13, Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Condensed Matter Physics Center (IFIMAC), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Institute for Advanced Research in Chemical Science (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Correspondence: (S.D.-T.); (G.G.)
| | - Ana I. Lozano
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (S.K.); (A.I.L.); (M.M.); (P.L.-V.)
| | - Mónica Mendes
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (S.K.); (A.I.L.); (M.M.); (P.L.-V.)
| | - Juan C. Oller
- Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense 22, 28040 Madrid, Spain;
| | - Paulo Limão-Vieira
- Laboratório de Colisões Atómicas e Moleculares, CEFITEC, Departamento de Física, Faculdade de Ciências e Tecnologia, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; (S.K.); (A.I.L.); (M.M.); (P.L.-V.)
| | - Gustavo García
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain;
- Centre for Medical Radiation Physics, University of Wollongong, Wollomgong, NSW 2522, Australia
- Correspondence: (S.D.-T.); (G.G.)
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6
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Lozano AI, Costa F, Ren X, Dorn A, Álvarez L, Blanco F, Limão-Vieira P, García G. Double and Triple Differential Cross Sections for Single Ionization of Benzene by Electron Impact. Int J Mol Sci 2021; 22:4601. [PMID: 33925653 PMCID: PMC8124667 DOI: 10.3390/ijms22094601] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2021] [Revised: 04/21/2021] [Accepted: 04/23/2021] [Indexed: 12/01/2022] Open
Abstract
Experimental results for the electron impact ionization of benzene, providing double (DDCS) and triple differential cross sections (TDCS) at the incident energy of 90 eV, measured with a multi-particle momentum spectrometer, are reported in this paper. The most intense ionization channel is assigned to the parent ion (C6H6+) formation. The DDCS values are presented for three different transferred energies, namely 30, 40 and 50 eV. The present TDCS are given for two fixed values of the ejected electron energy (E2), at 5 and 10 eV, and an electron scattering angle (θ1) of 10°. Different features related to the molecular orbitals of benzene from where the electron is extracted are observed. In addition, a semi-empirical formula to be used as the inelastic angular distribution function in electron transport simulations has been derived from the present DDCS result and compared with other expressions available in the literature.
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Affiliation(s)
- Ana I. Lozano
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain; (F.C.); (L.Á.)
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal;
| | - Filipe Costa
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain; (F.C.); (L.Á.)
| | - Xueguang Ren
- Max Planck Institute for Nuclear Physics, 69117 Heidelberg, Germany; (X.R.); (A.D.)
| | - Alexander Dorn
- Max Planck Institute for Nuclear Physics, 69117 Heidelberg, Germany; (X.R.); (A.D.)
| | - Lidia Álvarez
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain; (F.C.); (L.Á.)
| | - Francisco Blanco
- Departamento de Estructura de la Materia Física Térmica y Electrónica e IPARCOS, Universidad Complutense de Madrid, Plaza de Ciencias 1, 28040 Madrid, Spain;
| | - Paulo Limão-Vieira
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal;
| | - Gustavo García
- Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas, Serrano 113-bis, 28006 Madrid, Spain; (F.C.); (L.Á.)
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Thodika M, Mackouse N, Matsika S. Description of Two-Particle One-Hole Electronic Resonances Using Orbital Stabilization Methods. J Phys Chem A 2020; 124:9011-9020. [DOI: 10.1021/acs.jpca.0c07904] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Affiliation(s)
- Mushir Thodika
- Department of Chemistry, Temple University, 1901 N 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Nathan Mackouse
- Department of Chemistry, Temple University, 1901 N 13th Street, Philadelphia, Pennsylvania 19122, United States
| | - Spiridoula Matsika
- Department of Chemistry, Temple University, 1901 N 13th Street, Philadelphia, Pennsylvania 19122, United States
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8
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A Complete Cross Section Data Set for Electron Scattering by Pyridine: Modelling Electron Transport in the Energy Range 0-100 eV. Int J Mol Sci 2020; 21:ijms21186947. [PMID: 32971806 PMCID: PMC7555704 DOI: 10.3390/ijms21186947] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 12/11/2022] Open
Abstract
Electron scattering cross sections for pyridine in the energy range 0–100 eV, which we previously measured or calculated, have been critically compiled and complemented here with new measurements of electron energy loss spectra and double differential ionization cross sections. Experimental techniques employed in this study include a linear transmission apparatus and a reaction microscope system. To fulfill the transport model requirements, theoretical data have been recalculated within our independent atom model with screening corrected additivity rule and interference effects (IAM-SCAR) method for energies above 10 eV. In addition, results from the R-matrix and Schwinger multichannel with pseudopotential methods, for energies below 15 eV and 20 eV, respectively, are presented here. The reliability of this complete data set has been evaluated by comparing the simulated energy distribution of electrons transmitted through pyridine, with that observed in an electron-gas transmission experiment under magnetic confinement conditions. In addition, our representation of the angular distribution of the inelastically scattered electrons is discussed on the basis of the present double differential cross section experimental results.
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9
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Álvarez L, Costa F, Lozano AI, Oller JC, Muñoz A, Blanco F, Limão-Vieira P, White RD, Brunger MJ, García G. Electron scattering cross sections from nitrobenzene in the energy range 0.4-1000 eV: the role of dipole interactions in measurements and calculations. Phys Chem Chem Phys 2020; 22:13505-13515. [PMID: 32530024 DOI: 10.1039/d0cp02039g] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Absolute total electron scattering cross sections (TCS) for nitrobenzene molecules with impact energies from 0.4 to 1000 eV have been measured by means of two different electron-transmission experimental arrangements. For the lower energies (0.4-250 eV) a magnetically confined electron beam system has been used, while for energies above 100 eV a linear beam transmission technique with high angular resolution allowed accurate measurements up to 1000 eV impact energy. In both cases random uncertainties were maintained below 5-8%. Systematic errors arising from the angular and energy resolution limits of each apparatus are analysed in detail and quantified with the help of our theoretical calculations. Differential elastic and integral elastic, excitation and ionisation as well as momentum transfer cross sections have been calculated, for the whole energy range considered here, by using an independent atom model in combination with the screening corrected additivity rule method including interference effects (IAM-SCARI). Due to the significant permanent dipole moment of nitrobenzene, additional differential and integral rotational excitation cross sections have been calculated in the framework of the Born approximation. If we ignore the rotational excitations, our calculated total cross section agrees well with our experimental results for impact energies above 15 eV. Additionally, they overlap at 10 eV with the low energy Schwinger Multichannel method with Pseudo Potentials (SMCPP) calculation available in the literature (L. S. Maioli and M. H. F. Bettega, J. Chem. Phys., 2017, 147, 164305). We find a broad feature in the experimental TCS at around 1.0 eV, which has been related to the formation of the NO2- anion and assigned to the π*(b1) resonance, according to previous mass spectra available in the literature. Other local maxima in the TCSs are found at 4.0 ± 0.2 and 5.0 ± 0.2 eV and are assigned to core excited resonances leading to the formation of the NO2- and O2- anions, respectively. Finally, for energies below 10 eV, differences found between the present measurements, the SMCPP calculation and our previous data for non-polar benzene have revealed the importance of accurately calculating the rotational excitation contribution to the TCS before comparing theoretical and experimental data. This comparison suggests that our dipole-Born calculation for nitrobenzene overestimates the magnitude of the rotational excitation cross sections below 10 eV.
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Affiliation(s)
- L Álvarez
- Instituto de Fisica Fundamental, CSIC, Serrano 113-Bis, E-28006 Madrid, Spain.
| | - F Costa
- Instituto de Fisica Fundamental, CSIC, Serrano 113-Bis, E-28006 Madrid, Spain.
| | - A I Lozano
- Instituto de Fisica Fundamental, CSIC, Serrano 113-Bis, E-28006 Madrid, Spain. and Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - J C Oller
- Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense 22, 28040 Madrid, Spain
| | - A Muñoz
- Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense 22, 28040 Madrid, Spain
| | - F Blanco
- Departamento de Estructura de la Materia Física Térmica y Electrónica e IPARCOS, Universidad Complutense de Madrid, Plaza de Ciencias 1, 28040 Madrid, Spain
| | - P Limão-Vieira
- Atomic and Molecular Collisions Laboratory, CEFITEC, Department of Physics, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal
| | - R D White
- College of Science and Engineering, James Cook University, Townsville, Australia
| | - M J Brunger
- College of Science and Engineering, Flinders University, GPO Box 2100, Adelaide, SA 5001, Australia and Department of Actuarial Science and Applied Statistics, Faculty of Business and Information Science UCSI, Kuala Lumpur 56000, Malaysia
| | - G García
- Instituto de Fisica Fundamental, CSIC, Serrano 113-Bis, E-28006 Madrid, Spain. and Centre for Medical Radiation Physics, University of Wollongong, NSW, Australia
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