The TFD score between two structures represents a weighted sum of torsional differences as defined by Schulz-Gasch et al. in 2012 . Torsions central to the molecule are given more weight than torsions on the periphery of the molecule. Similarly with RMSD, geometric similarity is inversely correlated with TFD score. TFD scores range from 0 to 1, with 0 being most similar and 1 being most different. The authors of TFD consider scores over 0.2 to represent significantly different geometries. In contrast to RMSD, TFD is bounded and less sensitive to molecular size, making it particularly helpful here.