The difference between Hirshfled and MBIS charges performance is interesting, since both charges models are derived by partitioning the molecular electronic density within the atomsin-molecules framework. MBIS charges can actually be considered a variant of the Hirshfeld model, but differ in the way the so-called pro-atomic densities are determined, being also considered a density-fitting scheme. Our results suggest that the MBIS partitioning scheme reproduces the electron density behavior, at least regarding the calculation of the ML/MM coupling energy.