Table 2 General limit required for the QSAR model assessment

R²_trng

Squared correlation coefficient of training set

≥ 0.6

0.8764

Q_cv²

Cross-validation coefficient

≥ 0.5

0.7655

R² − Q²

Difference between R² and Q²

≤ 0.3

0.1109

N_{(test set)}

Minimum number of external test set

≥ 5

5

R²_ext.

Squared correlation coefficient of test set

≥ 0.5

0.7024