“…Based on a vibrationally diabatic model, they concluded that there is a significant enhancement in reaction rate when the CH 4 symmetric stretching mode is excited, which is subsequently confirmed by a recent experiment 31 . Several other potential energy surfaces (PESs) have been produced, 7–14 and used in quasiclassical trajectory studies (QCT) 11,14–17 and reduced dimensionality quantum dynamics calculations 8,9,18–21 . In addition, there have been direct dynamics calculations on this system 22,23 and numerous calculations based on variational transition state theory 6,7,10,14,24,25,27,29,30 …”