Electron-impact cross sections of X2CO (X = H, F, Cl, Br) from ionization threshold to 5 keV

Abstract

Various electron-impact cross sections are obtained for halogenated derivatives of formaldehyde like H2CO, F2CO, Cl2CO, Br2CO using the Single Centre Expansion method. The molecular wavefunction of the targets are obtained from the multi-centre expansion of the Gaussian-type orbitals within the single determinant Hartree Fock self consistent field scheme. The effects due to static, correlation-polarization and exchange included to model the electron-molecule interactions are approximated by their local nature. The correlation-polarization potential includes short and long range polarization electron dynamical effects. The dipole and higher order multipole terms are considered in the multipole expansion of the target at centre of mass. The coupled scattering equations are solved using Volterra integral form to obtain the elastic cross sections. The inelastic contributions to collision process are approximated by ionization cross sections. The two cross sections are added to obtain the total cross sections from ionization threshold to 5 keV. The collision data generated from this approach are consistent with the available results. The study of scattering from homologous series has helped in proposing a simple empirical formula to estimate the total cross sections for any member of the homologous family.