Critical analysis of the modified firsov model. sensitivity to the choice of atomic wavefunctions

Abstract The Firsov model for calculating the low-velocity e-lectronic stopping power (Se) as modified by Cheshire, et al, is found to be extremely sensitive to the choice of atomic wave functions (ψ) when a minimum impact parameter is used in the calculations. Differences of a factor of ≃2 are observed, for example, between the predicted value of Se using a minimal basis set for ψ and the value obtained using an extended basis set. A systematic analysis to reduce the sources of uncertainty in calculations of S e is proposed in order to have a unified set of criteria regarding the predictions of the theory.