The ME principle involves ranking isomers of the same molecular composition based on their zero-point energycorrected total energy, first calculated using the PM7 method ; ; . If the energy difference between the lowest-energy isomer and the second-lowest isomer is ≤ 5 kcal/mol, both isomers are retained. These isomers are then re-optimized using a more accurate density functional theory (DFT) method (detailed in Section 3), and those with DFT energy differences ≤ 5 kcal/mol are kept for further analysis.