P() being the product normalized probability of reactive trajectories with angle , which is obtained from a histogram analysis by dividing the range [0,180º] into intervals of 10º and counting the number of trajectories per interval. Finally, the Legendre moment method was used to fit the DCS and to smooth this histogram. Figure plots the PADs for the title reaction (solid line) together with the scattering angle for the CN + CH4 reaction obtained by our group using PES-2017, both at 298 K. Both distributions present a clear backward distribution, associated with a rebound mechanism, clearer in the case of methane reaction. This behaviour is related with the scattering angle/impact parameter relation, i.e., small impact parameters favour backward scattering. While ethane presents a maximum impact parameter of 6.5 Å, the reaction with methane presents a smaller value, 2.6 Å, thus favouring a more backward distribution. As in the cases of PRD and PTD, the PADs simulate previous theoretical and experimental backward distributions in other alkanes (from propane to hexane), although as was previously noted, the initial conditions were different. Again, these results suggest a general tendency in the CN + alkane reactions. Before finishing this Section, we consider the evolution of the DCSs with temperature (equivalent to the initial collision energy).