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The present study aims to quantify the electron-induced inelastic and elastic processes for molecules of industrial relevance, furfural and p-benzoquinone. We have computed inelastic cross-sections (Qinel), elastic cross-sections (Qel) and total cross-sections (QT) through spherical complex optical potential (SCOP) formalism, from ionisation energy (IE) to 5000 eV. The continuum and discrete contributions of the Qinel have been calculated in terms of ionisation (Qion) and excitation (∑Qexc) cross-sections, respectively, by employing the complex scattering potential-ionisation contribution (CSP-iC) method. A novel 2-parameter semi-empirical method (2p-SEM), a useful approach applicable for the large molecules 55 < Z < 95 for calculating QT, has been proposed and validated. Computed results are compared with previous experimental and theoretical data. We have also estimated the dielectric constant (ε) using various methods and correlations with molecular ionisation for these applied molecules. [ABSTRACT FROM AUTHOR]

Linear carbon series cyanopolyacetylenes (HC2n+1N) (n = 3, 4, and 5) are astromolecules found in the atmosphere of Titan and interstellar media such as TMC-1 (Taurus molecular cloud-1). All these compounds are also detected in IRC + 10216. In the present work, we comprehensively investigate electron interaction with important cyanopolyacetylene compounds, viz. HC7N (cyano-tri-acetylene), HC9N (cyano-tetraacetylene), and HC11N (cyano-penta-acetylene). The study covers incident electron energies ranging from the ionization threshold to 5 keV. Various electron-driven molecular processes are quantified in terms of total cross-sections. The quantum spherical complex optical potential (SCOP) is used to determine elastic (Qel) and inelastic (Qinel) cross-sections. Ionization is the most important inelastic effect that opens various chemical pathways for the generation of different molecular species; we computed the ionization crosssection (Qion) and discrete electronic excitation cross-section (SQexc) using the complex scattering potential-ionization contribution (CSP-ic) method. The cyanopolyacetylene compounds are difficult to handle experimentally owing to the health risks involved. Therefore, there are no prior experimental data available for these molecules; only Qion have been reported theoretically. Thus, the present work is the maiden report on computing Qel, Qinel, SQexc, and QT. In order to provide an alternative approach and further validation of the present work, we employed our recently developed two-parameter semi-empirical method (2p-SEM) to compute Qel and QT. Additionally, we predict the polarizability of the HC11N molecule, which has not been reported in the existing literature. This prediction is based on a correlation study of polarizabilities of molecules with Qion values from the same series of molecules. [ABSTRACT FROM AUTHOR]

In this comprehensive study, we explored the molecular chemistry of H2O, CO2, and NH3 molecules in their gas and ice phases assisted by electron and positron interactions over a wide range of energy from threshold to 5000 eV. These simple molecules have immense applications in areas such as atmospheric sciences and astrochemistry. We employed the spherical complex optical potential (SCOP) model along with the complex scattering potential-ionization contribution (CSP-ic) model and modified them to quantify the probabilities of various charged particle-driven molecular processes through inelastic cross-sections (Qinel), total ionization cross-sections (Qion), direct ionization cross-sections (QD-ion), and positronium formation cross-sections (QPs) for these molecules in gas and ice phases. We propose a novel model that incorporates the band gap of a material for positron impact cross-sections with molecules in their condensed phase. This is the first study on electron interactions with NH3 (ice) and positron interactions with H2O, CO2, and NH3 in their condensed phase. [ABSTRACT FROM AUTHOR]

This paper reports computational results of the total cross sections for electron impact on formamide (HCONH2) over a wide range of energies from 0.01 eV to 5keV. Total cross sections over such a wide range are reported for the first time as the earlier reported data is up to maximum of 12 eV. Below ionization threshold of the target, we performed ab initio calculations using UK molecular R-Matrix code within static, exchange plus polarization (SEP), and close coupling approximations. Twenty eight target states are included in close coupling formalism. Total 350 channels and 2410 configuration state functions are included in the calculations. We observe a π* shape resonance at 3.41 eV and a σ* resonance at 15.3 eV as against similar resonances reported at 3.77eV and 14.9eV, respectively, by Goumans et al. [J. Chem. Theory Comput. 5, 217 (2009)] using SEP model. The cross sections at higher energies are evaluated using the spherical complex optical potential formalism. The two methods are found to be consistent with a smooth cross over at 18 eV. The vertical excitation energies, electronic excitation cross sections, differential cross sections, momentum transfer, and total cross sections are computed. In absence of experimental data, we compared our computed total cross sections with available other theoretical results. [ABSTRACT FROM AUTHOR]

We report the measurement of the absolute double differential cross sections (DDCS) of secondary electrons emitted due to the ionization of N2 molecule in collisions with fast electrons having energies between 3 and 5 keV. The emitted electrons with energies from 1–500 eV have been measured for different forward and backward emission angles. The measured DDCS have been compared with the state-of-the-art first Born approximation with correct boundary condition (CB1) model calculations as well as with the classical trajectory Monte Carlo (CTMC) method. From the measured DDCS, the single differential cross sections (SDCS) as a function of the emission energies have been computed and eventually the total ionization cross sections (TCS) have been derived. The TCS values are also compared with a semi-empirical calculation, namely, the CSP-ic (complex scattering potential-ionization contribution) model. [ABSTRACT FROM AUTHOR]

In this article, we report a detailed theoretical study on electron interactions with chlorobenzene with incident energies ranging from 0.1 to 5000 eV. Due to this wide range of impact energy, we are able to investigate a variety of processes and report data on resonances, differential cross-sections (DCS), momentum transfer cross-sections (MTCS), rate coefficient, vertical electronic excitations, dissociative electron attachment (DEA), total ionisation cross-sections and total scattering cross-sections (TCS). In order to compute the total scattering cross-sections, we have employed the ab-initio R-matrix method via Quantemol-N for the lower energy range (0.1 eV to 20 eV) and Spherical Complex Optical Potential (SCOP) beyond threshold energy of the target to 5000 eV. The R-matrix calculations are performed using a close-coupling method with the aid of 34 target states, 1667 configuration state functions, and 233 channels employing Configuration Interaction (CI) model. The present study reports evidence for electron scattering resonances through analysis of eigenphase diagrams fitting them to Breit-Wigner profile at low energies below the ionisation threshold. [ABSTRACT FROM AUTHOR]