“…where log(IC 50 )/HA is ligand efficiency (HA is the number of ligands' heavy atoms), r 2 77 is the correlation coefficient against 77 training compounds, r 2 LOO is the leave-one-out cross-validation correlation coefficient, and r 2 PRESS is the predictive r 2 determined for 19 randomly selected test compounds (1,5,11,14,17,23,32,42,45,50,51,64,67,74,78,128,138,139, and 141, as inTable S1 under supporting information).r 2 m and Δr 2 m are the average and delta r 2 m values calculated for training compounds, respectively. These are recently developed metrics that extensively test the internal and external predictive capacities of a QSAR model through establishing the proximity between predicted and observed response data among training compounds.…”