The SAMPL6 organizers initially provided an approximate evaluation of predicted microscopic transitions using macroscopic pK a s. Organizers provided experimental macroscopic pK a s for all molecules, but experiments for microscopic pK a s were only performed for seven molecules . In an attempt to provide feedback on type I predictions, organizers compared experimental data for molecules with only one experimental pK a or two pK a s with a difference greater than 3 relative to microscopic predictions. For each molecule, the experimental values were matched to microscopic predictions that resulted in the lowest error, using the same closest Fig. NMR experiments were performed for molecules SM07 and SM14. SM07 has one microscopic transition for the protonation of the top nitrogen (green). SM14 has two microscopic transitions, first the protonation of the middle nitrogen (yellow) and then the left nitrogen (green). For both molecules, we highlight the other nitrogens we identified as ionizable (blue).