In short, we believe that in most cases the correlation between experimental crystallographic geometries and gas-phase conformer sampling with semiempirical quantum methods such as GFN2 are high enough to derive accurate torsional preferences. This is consistent with previous comparisons of energetic rankings of conformers between GFN2 and higher-level quantum chemical methods including density functional and coupled cluster calculations, as well as efforts to estimate torsional strain in crystal structures using DFT methods. Ring torsional patterns, constrained by the nature of a ring, show even greater correlation, with the median r 2 at 0.83 (Figure ) and few patterns (16 out of 105) showing correlation below 0.5, again correlated with few matches. Individual acyclic torsional preferences can be further analyzed to determine the qualitative correlation between the crystal structures and gas-phase conformers. Torsion pattern 229 shown in Figure demonstrates a high degree of correlation (r 2 = 0.76) between the crystal structures and gas-phase CREST/GFN2 lowest energy conformers, while demonstrating the advantage of using additional data from the entire set of compounds. Pattern 229 has only 179 torsions from the COD, while the expanded data set boasts over 25,000