Fault in PM6 in Prediction that R-COO-R + R-NH2 forms a stable system


PM6 predicts that an organic acid and an amine should react to form a stable C-N bond.  The fault does not appear with simple compounds, but can be shown in a more complicated system.

In this fault, R-NH2 reacts with R-COO-R to give R-NH2-C(R)OOR.  The NH2 is formally positive, and the C=O becomes C-O(-).