All geometry optimizations were performed using the M06-2X 79 and ωB97X-D 78 global hybrid functionals, each combined with the 6-31G(d), 6-31G(d,p), 6-31+G(df), 6-31+G(df,p) split-valence basis sets and using the Gaussian 16 package of programs. The pyramidal inversion of ammonia, phosphine, and arsine was conducted following the IRC path with a step size equal to 0.001 amu 1/2 Bohr. In contrast, a relaxed scan with a step of 0.010 Bohr was employed for studying the dissociation of ethane, ammonia borane, and phosphine borane molecules. For the former system, the multiconfigurational character due to the spin multiplicity was assessed through the complete active-space self-consistent field (CASSCF) 105 employing the same number, six and eight, of electrons and virtual orbitals using ORCA 5.0. 106 The energy was further corrected via a CAS second-order perturbation theory (CASPT2). The topological analysis of the ELF and the characterization of its phase space were carried out using the Multiwfn program. The images of the topographic map were generated using the VMD software. The fulfillment of the Poincaré-Hopf theorem was verified for all topographic maps along the pathway. The classification of bifurcations was carried out by strictly examining the absolute value of the Hessian determinant evaluated at all potentially degenerate critical points and their relative distance near the degeneration region.