Similar to the prediction of a single target discussed above, e k ij and s k ij cannot be correlated per atom, because again a single committee prediction corresponds to a single draw from a distribution centered around the target with a width determined by s k ij / √ N C . However, we can utilize force predictions averaged over sets of atoms to correlate variance error with uncertainty. Namely, by averaging over all directions k and atoms j, we arrive at a per-structure mean absolute error of