Up to four diverse conformers for each fragment were produced, using OMEGA from OpenEye Table . The performance of Sage and BespokeFit parameters on the fragmented Wang dataset , using the default QC chemistry as the reference method. The final two rows test details of the parameter optimization procedure (with differences in procedure noted in parentheses), as described in the main text. the torsion scans. The workflow resulted in a torsion drive dataset comprising 490 molecular fragments and 671 unique scans. OpenFF QCSubmit was then used to submit the dataset to the public QCArchive instance with two different compute specifications, the default OpenFF QC method (B3LYP-D3BJ/DZVP ), using the PSI4 package , and the GFN2-xTB semi-empirical method (Supporting Information Section S1.1). Once all of the calculations were complete, a local BespokeFit server was set up to generate and optimize bespoke torsion parameters. Each fragment was initially parametrized using the base OpenFF 2.0.0 (Sage), and then torsion parameters were optimized against the chosen reference data (that is, either the default QC or the xTB torsion scans), following the procedure described in Section 2.6.