A study of electron scattering from 1-1 C2H2F2 from 0.1 eV to 5 keV

Abstract

Various electron- impact cross sections of 1-1-C2H2F2 molecule are reported in the energy range from 0.1 to 5000 eV using the cc-pVTZ basis set. The molecular wavefunctions of the target are obtained from the multi-center expansion of the Gaussian-type orbitals within a single determinant Hartree Fock self consistent field scheme. The elastic cross sections in the low energy range (below ionization threshold) are reported in different scattering models like static-exchange, static-exchange-polarization and close-coupling using the R-matrix approach. The resonances detected in these scattering models are comprehensively analysed. The computed shape resonances are in an excellent agreement with the experimental and theoretical values. In addition to elastic rate coefficients, we have also reported differential, momentum transfer and electronic excitation cross sections. The present elastic cross sections are in good accord with the other ab-initio calculations. However, the total cross sections obtained lie systematically above the experimental results. The Single Center Expansion (SCE) involving the use of local potentials is invoked to obtain differential, elastic and momentum transfer cross sections at energies beyond ionization threshold. The ionization cross sections are obtained using the Binary-Encounter-Bethe model. The total cross sections are obtained by incoherently summing the elastic and inelastic cross sections. The SCE based results and total cross sections are in good agreement with the experimental and theoretical results. The cross sections like elastic, momentum transfer and total obtained from two different approaches are found to match smoothly near ionization threshold thus helping in estimating the cross sections over a wide energy range.