for B3LYP and BLYP, respectively (Supplementary Material Figure ). The similar optimal ε observed here is likely due to the similarity of the tested zwitterions in both chemistry and sizes, whereas the optimal ε in general vary with the system calculated. However, the Bader charges for cations are significantly lower than other charge models. The Bader charges for cationic Cterminals obtained with CCSD(T) are lower than that for gas-phase BLYP, meaning that further applying CPCM will worsen the results compared to CCSD(T). We checked the partition of the Bader charge analysis regions and found a clear difference between the partitions for CCSD(T)