Total CSs for the electron exchange reaction of He^+⋅ with CH₃CN as a function of collision energy (E). The black filled circles are the total relative CSs, rescaled as detailed in the text. The lines represent total CSs as estimated from the following capture models: Langevin (black solid line), averaged dipole orientation (ADO) (blue short dashed line) (Bass et al. 1975; Su et al. 1978; Tsikritea et al. 2022) and the average cosθ approach (Kosmas 1984)(magenta dashed line). The solid red line represents the computed CSs according to the theoretical treatment, based on an improved Landau-Zener-Stückelberg approach, and detailed in Sections 3 and 4.4. Error bars on the total relative CSs are ±40%.