where r, R, and Ψ !" denote the electronic and nuclear coordinates and the electronic wave function, respectively. The electronic density is a real-valued scalar field, lending itself to topological analysis and the extraction of topological features 𝑓 & . One way to analyze such topology is to study critical points (CPs), i.e., locations in the density where the gradient vanishes, ∇𝜌 = 𝟎, or is undefined. The critical points form a concise set of features that yield insight into the molecular structure.