While errors in dihedral / torsion angles exist, the purpose of this study is not to find the conformer that best matches experiment by generating various conformers, but rapidly generating initial geometries for further processing. Some evaluation papers (e.g. ) report better RMSD for RDKit or Confab. This is because they generate multiple, geometrically diverse conformers and to find the best RMSD. Such conformer generation is recommended subsequent to creating an initial threedimensional geometry if desired. Analysis of Problem Molecules We find that 9.6% of molecules have RMSD above 3.5 Å or incorrect stereochemistry, compared to 26.8% for the original Open Babel implementation, and only 2.8% for RDKit ETKDG. Figure shows two examples of predicted molecule with high RMSD. In both cases, the main differences between experimental and predicted structures come from inter-fragment dihedral angles. In the bottom example, Figure ) the predicted conformation is more extended than in experiment. While additional post-processing with conformational searches help to minimize such differences, further work to find patterns of inter-fragment dihedral angle preferences will also improve initial predictions. Beyond poor placement of fragments and choice of dihedral angles, some molecules exhibit incorrect stereochemistry after coordinate generation. Figure shows two examples of molecule with stereochemistry errors. In the first case, an incorrect geometry at the circled carbon yields a difference in streochemistry after hydrogen atom placement.