These principal components may lack physical meaning by themselves because they may act as statistical descriptors. Nevertheless, we could still assess the physical meaning of each PC according to the energy terms of each scoring function. To the best of our knowledge, the physical meaning of PC1 could be attributed to van der Waals interactions, the physical meaning of PC2 could be attributed to electrostatic interactions, and the physical meaning of PC3 could be attributed to the hydrophobic interactions between the protein and ligands.