This analysis reveals that the inversion of the ammonia molecule only triggers flags for the most basic parametric function of Thom's catastrophe theory, contradicting a previous report. This significantly simplifies the topological rationalization of this reaction by eliminating the umbilic complexities because this unfolding is not a cuspoid, which means that it has more than one state variable, and more importantly, three (control) parameters are needed to remove its degenerations entirely. The parameter of the fold function typically has a straightforward physical interpretation. One suitable alternative for the chemical process at hand is the angular displacement (μ) conveniently defined by the C3 axis and the N-H bonds. See Ref. 29 for further details on the critical values of this parameter. In this scenario, smooth changes in μ lead to the creation/annihilation of (attractor, saddle) pairs when a critical value μ ͙ is reached, ''jumping'' the reacting system between regions (structural stability domains) with any and two CPs, as displayed in Figure . In essence, within this succinct topographical description of the ammonia pyramidal inversion, μ controls the changes in sp hybridization. However, it is crucial to underscore that giving a specific interpretation to each parameter in the context of the umbilic catastrophe remains a challenging task.