Assessment of seventeen density functionals to estimate the global reactivity of C₂₀ in the framework of the conceptual density functional theory

A set of seventeen density functionals encompassing three Jacob's ladder rungs were analyzed to estimate the global reactivity of C₂₀ by Koopmans’ theorem considering as a reference the finite difference approximation which is the most accurate way to compute some well-known global reactivity descriptors. Our findings revealed that the ωB97X-D density functional surmounts the performance of the sixteen remaining density functionals. A comparison against the global reactivity of C₆₀ revealed that C₂₀ has a relative electron-accepting power that is about 1.2 eV lower than that of C₆₀.