The authors of both calculated methods validated these methods against BLM experimental data 22,23 . Bittermann et al. report that COSMOperm has RMSE = 0.62 log units for neutral molecules and RMSE = 0.7 log units for ions. The PerMM method has RMSE = 1.15 log unit by Lomize et al. . Therefore, it is no surprise that these methods correlate strongly. In addition, highly similar BLM datasets were used for validation, and this validation data comprises the majority of the BLM data in the MolMeDB database. We also see that the values are wide ranged because BLM, COSMOperm, and PerMM are methods that are not constrained by diffusion limits and provide intrinsic permeabilities.