The electron capture cross section using the r-CTMC method: a review and a suggestion for improvement

In this work we review the classical recipe for estimating partial cross sections for electron capture into selected energy levels within the Classical Trajectory Monte Carlo (CTMC) method [R.L. Becker and A.D. MacKellar, J. Phys. B: At. Mol. Phys. 17 (1984) 3923], and point to a deficiency of the method when applied to the CTMC in its r-version, according to the terminology introduced by Cohen [J.S. Cohen, J. Phys. B: At. Mol. Phys. 18 (1985) 1759]. We suggest, in this case, an alternative recipe based on the generation of stationary classical spatial distributions for electrons in arbitrary levels. The output of the CTMC simulations is projected onto these classical distributions rather than on the quantal ones. A comparison between the two approaches is done.