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A comprehensive theoretical study of electron scattering with thiophene over a wide impact energy range is reported in this article.

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 5 keV. 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 3.77 eV and 14.9 eV, 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.

A detailed theoretical study is carried out for electron interactions with acetaldehyde (CH 3 CHO) with impact energies ranging from 0.01 to 5000 eV. Owing to the wide energy range we have been able to investigate variety of processes and report data on Dissociative Electron Attachment (DEA) through resonances, vertical electronic excitation energies, differential, momentum transfer, ionization and total cross sections (TCS) as well as scattering rate coefficients. In order to compute TCS we have employed ab initio R-matrix method (0.01 to $20 eV) and the spherical complex optical potential (SCOP) method ($20 to 5000 eV). The Rmatrix calculations are performed using close coupling method employing static exchange plus polarization model. We have employed different target models and basis sets to study their effect on the target parameters as well as total cross sections. We observed two strong resonances, one at 1.33 eV which corresponds to 2A 00 symmetry with a width of 0.1726 eV which is in agreement with 1.30 predicted earlier experimentally by van Veen et al. and other resonance at 10.03 eV of 2A 0 symmetry with 0.0688 eV width which is close to 10.00 eV reported experimentally by Szymanska. The first peak corresponds to capture of an electron in to the lowest vacant p* orbital of the carbonyl group while the second corresponds to s* core excited shape resonance which is responsible for the O À fragment. We observed many fragments of CH 3 CHO in our eigenphase sum study which are in accordance with the earlier reported data. The scattering rate coefficients and theoretical TCS data beyond 30 eV are reported for the first time. Further, no experimental data for TCS is available beyond 400 eV to the best of our knowledge. We have compared all our results with available data in the literature and found overall good agreement. Due to dearth of TCS data for acetaldehyde, we have also compared the TCS of acetaldehyde with its analogue targets such as formic acid, formaldehyde, formamide and ethylene oxide and drawn conclusions.

A comprehensive theoretical study was carried out for electron interactions with thioformaldehyde (H2CS) over a wide range of impact energies (0.01 eV to 5000 eV).