We assess the quality of energy modelling by evaluating the prediction MAE and Continuous Ranked Probability Score (CRPS) of the posterior predictive distributions . CRPS is a proper scoring rule regularly used to assess probabilistic prediction skill, which accounts for both accuracy and precision. For the probabilistic predictions from the GPR, CRPS provides a meaningful way of evaluating the distance between the posterior predictive distribution and the test observations. For a deterministic point prediction, e.g. simply using values of force field energies, CPRS corresponds with MAE. As we obtain a separate posterior predictive distribution for each structure, we will be using the mean of the scores calculated for N t structures: