However, our choice of 5 Å maximum is to optimize structures at the DFT level in a feasible time. We have optimized these 762 ligands at the WB97X/6-31G* level and re-compared the RMSD values (between model and ideal structures) upon optimization. Only 439 structures with RMSD≥2 Å between model and ideal (i.e., scenario 2 is applied) and that RMSD≤2 Å between optimized model and un-optimized model structures (i.e., scenario 3 is applied) have remained after this step. These structures are assured to hold different "model" and "ideal" QM optimized conformations. Our aim for assessing the performance of the conformer generation is the ability to find the QM optimized "model" structure when QM optimized "ideal" structure is introduced to the program among these final 439 selected structures (Table ).