Total Scattering Cross Sections Calculations for Electron Impact on CF2 Radical

Abstract

Total scattering cross sections for electron impact on CF₂ in the gas phase are presented from 0.1 eV to 2000 eV. Computation of such e - CF₂ cross sections over such a wide range of energy is reported for the first time employing two distinct formalisms. From 0.1 eV to the ionization threshold of the target we employed the ab-initio R-matrix method, while at higher energies we used the Spherical Complex Optical Potential (SCOP) method. At the crossing point, the two theories match one another quite well and hence prove that they are consistent with one another. A quantum chemistry code is utilized to generate the target properties which are in good agreement with earlier reported data. The calculations show a peak at 0.81 eV using the Static Exchange Polarization (SEP) model and at 1.86 eV using a Static Exchange (SE) model which is a reflection of the formation of a shape resonance state. These values are close to theoretical calculations by Rozum et al. [J. Phys. Chem. Ref. data, 35, 267 (2006)] with a peak at 0.89 eV for SEP model and 1.91 eV for SE model. Lee et al. [Phys. Rev. A, 74, 052716 (2006)] have also reported a peak at 1.65 eV. The total cross sections presented here are in good agreement with other experimental and theoretical calculations. These results show that the techniques employed here can be used to predict cross sections for other targets for which data is scarce or not available. This methodology maybe integrated into online databases such as the Virtual Atomic and Molecular Data Centre (VAMDC) to provide cross section data required by many desperate users.