As a further experiment, we have also re-run the free energy calculations using the BespokeFit FF fit to xTB torsion scans. Interestingly, as we saw in Table , the BespokeFit (GFN2-xTB) FF is intermediate in accuracy, on all measures, between the base FF and the FF fit to the default QC data. For example, the RMS error in binding free energies is 0.64 0.93 0.39 kcal/mol (Figure ). Whether this accuracy hierarchy holds more generally, however, will require further protein-ligand free energy benchmarking. Here, we simply present this case as an example application to protein-ligand binding to show that bespoke torsion parameter fits can be relevant to the accuracy of binding predictions.