Table 2.

Root Mean Squared Errors (kcal/mol) of Training and Testing Sets for Proton Transfer Reaction of Glycine with Q² Values (in Parentheses)^b

	training set	testing set
20a	1.22	1.25 (0.971)
40	1.20	1.30 (0.969)
80	1.28	1.29 (0.970)

^aNumber of configurations selected from each window for training. For the proton reaction of glycine the total number of samplings in the training set is the product of 25 and this number.

^bAb initio QM/MM potential energies for the proton transfer reaction of glycine are predicted with QM/MM-NN. Three training sets with different sizes and one testing set are used.