Cross-section studies of cyanoacetylene by electron impact

Abstract

The present article provides the first comprehensive study of electron scattering from the cyanoacetylene molecule. The results reported here include integral elastic cross-sections over a wide energy range (0.5 to 5000 eV) and differential, momentum transfer and electronic excitation cross-sections at low energies (<10 eV). For the computation of cross-sections over such a wide energy range, two formalisms are employed: the ab initio R-matrix method and the spherical complex-optical-potential method operating at low and high incident energies, respectively. The total ionization cross-section has also been calculated using the complex scattering potential-ionization contribution method and shows excellent agreement with previously reported values. The target parameters and resonance positions predicted by the R-matrix method are in reasonable agreement with, albeit limited, previous data. The resonances identified at low energies are associated to several dissociative electron-attachment channels.

Electron interactions with astro chemical compounds

“…The present results of Q el and Q T for HCN find good accord with the compared theoretical results [35][36][37] except at lower energies. For HCCCN, while the present Q ion results underestimate the theoretical data [38,39], present Q el show reasonable matching with Kaur et al [39] beyond 30 eV. The total ionization cross sections Q ion and the peak value Q ion (peak) are sensitive to the ionization potential (table 3).…”

“…In figure 9 we have shown present Q el for HCCCN as compared with the previous Q el data of Kaur et al [39] along with the present Q T for which we have not found any experimental or theoretical results in literature. We find large differences for present Q el with the Q el values of Kaur et al [39]…”

“…This behavior at the Q ion (peak) is mainly due to the lower Koopman ionisation potential [64] for In figure 3 we have displayed the results of HCCCN and have compared present results of Q ion with the previous BEB data of Gilmor and Field [38] and Kaur et al [39] as well as CSP-ic data of Kaur et al [39]. The present data underestimate both the previous work [38,39] but have similar nature of the cross section curve.…”

“…This behavior at the Q ion (peak) is mainly due to the lower Koopman ionisation potential [64] for In figure 3 we have displayed the results of HCCCN and have compared present results of Q ion with the previous BEB data of Gilmor and Field [38] and Kaur et al [39] as well as CSP-ic data of Kaur et al [39]. The present data underestimate both the previous work [38,39] but have similar nature of the cross section curve. Differences between the Q ion results obtained through CSP-ic and BEB formalisms are attributed to two aspects (1) In BEB method the ionization potential is computed using the Koopmans theorem [64] and it differs with most experimental ionization potential by about 1 eV.…”

Electron collisions with cyanoacetylene HC3N : Vibrational excitation and dissociative electron attachment

“…12,15 The latter group has initially reported a yield of indi-vidual fragment ions 12 and later recalibrated these yields using signal from background water vapor to determine the absolute partial cross section values. 15 Theoretically, the resonances in cyanoacetylene were explored by Sommerfeld and Knecht 16 with the complex absorbing potential approach, by Sebastianelli and Gianturco 17 with the single-center expansion scattering calculations and by Kaur et al 18 by R-matrix theory. Orel and Chourou 19 performed multidimensional nuclear dynamics calculations on the resonant states of HC 3 N.…”