Figures and present density plots illustrating the correlation between E elec ML/MM values obtained via mechanical embedding, E ME ML/MM , and the QM/MM electrostatic coupling energy at the electrostatic embedding level, E EE QM/MM . It is evident that mechanical embedding consistently underestimates the absolute value of the coupling energy compared to electrostatic embedding from DFT, and that such underestimation depends linearly on the QM/MM electrostatic energy (resulting in linear correlations). The calculated Mean Relative Absolute Difference (MRAD, equation (( ))) values show that Hirshfeld charges (ωb97x/6-31G*) yields the least favorable results (MRAD=0.5627). Across Mulliken charges derived from different levels of theory, a loss in accuracy is observed when transitioning from DFT (PBE/DZVP) to semi-empirical methods. Both the CM5 (ωb97x/6-31G*) and Mulliken approaches provide comparable outcomes, with the most favorable results observed when employing the MBIS partitioning scheme (MRAD=0.1739).