Experimental and theoretical elastic cross sections for electron collisions with the C3H6 isomers

Abstract

In the present work we report cross sections for electron collisions with the isomers propene (C3H6) and cyclopropane (c-C3H6). Electron-scattering differential cross sections (DCS) are reported for measurements carried out for energies 1.5-100 eV and the angular range of 20 degrees-120 degrees. Elastic integral cross sections (ECS), DCS, and momentum-transfer cross sections (MTCS) are reported for calculations carried out using the Schwinger multichannel method with pseudopotentials for the energy range of 2.0-40 eV and angular range of 0 degrees-180 degrees. The resemblance of the pi* shape resonance in the cross sections, observed at 1.5-2.0 eV for propene, to those in C2H4 and C2F4 clearly points to the effect of the double bond in the molecular structures for these molecules. Below 60 eV, we observed clear differences in peak positions and magnitudes between the DCS, ECS, and MTCS for C3H6 and c-C3H6, which we view as the isomer effect.

Electron-impact vibrational excitation of cyclopropane

“…(2). We find satisfactory agreement both for the integral elastic cross section plotted as a function of electron energy shown in 39 and squares, 40 while circles represent the previously reported total cross section. 41 Present experimental data are denoted by diamonds.…”

“…The present experimental data are shown with the black line, while the previous measurements are denoted by squares. 40 The red line shows present calculations, blue line displays results of previous Schwinger multi-channel calculations, 40 and the green line represents single-center expansion calculations. 42 may be assigned to the use of a single (electronic) channel model.…”

“…41 Present experimental data are denoted by diamonds. Present calculations are shown as red line, while the orange line represents previous SMC, 40 and blue line represents results of single-center expansion method. 42 The oldest SMC results 43 are omitted here for clarity reasons.…”

Recent advances in the application of the Schwinger multichannel method with pseudopotentials to electron-molecule collisions

“…The isomer effect allows one to distinguish between different isomers of a given molecule by differences in the scattering cross sections (total, integral elastic, differentials, rotation excitation). We investigated isomers of the hydrocarbons C 3 H 4 , C 4 H 6 , C 4 H 8 , C 4 H 10 and C 3 H 6 [74][75][76][77][78][79]. The results for energies between 10 eV and 40 eV, suggested that the integral cross sections for the isomeric group differed by a factor that could be obtained through a scaling law based on geometrical optics (in fact this is a general model that was applied for molecules other than hydrocarbons) [80].…”

Towards efficientab initiocalculations of electron scattering by polyatomic molecules: III. Modelling correlation–polarization interactions

“…Both molecules have been intensively studied experimentally (Allan 1994, Allan and Andric 1996, Szmytkowski et al 2002a, Makochekanwa et al 2006, Boesten et al 1994, Tanaka et al 1999. While number of theoretical calculations is thorough for the cyclopropane molecule (Winstead et al 1992, Beyer et al 1997,Čurík and Gianturco 2002a, Makochekanwa et al 2006, to our knowledge there is only one SE calculation by Winstead et al 1991 for the propane molecule. A visual comparison of the spherical components u 0 0 (r) defined by Eq.…”