Use of relativistic effective core potentials in the calculation of total electron-impact ionization cross-sections

The binary-encounter-Bethe (BEB) model of Kim and Rudd for total ionization cross-sections by electron impact is re-examined when the target is an atom with principal quantum number n⩾3, or a molecule consisting of one or more atoms with n⩾3. It is shown that the use of relativistic effective core potential (RECP) for heavy atoms removes the need for the empirical scaling used previously. BEB cross-sections of Ar, Kr, Xe, Cl, Br, I, and WF6 calculated using RECP are found to be in good agreement with available experimental data, especially in the low-energy region.