is the limit in the implementation by Laio et al., would require cutoff distances that are much larger. In fact, for the small solute-solvent systems, the forces are only fully converged when almost all solvent water molecules are treated via the short-range coupling while for the larger systems it requires larger cutoffs than those investigated here. The corresponding increase of the computational cost would by far exceed the cost associated with the use of a higher-order multipole expansion at shorter cutoff distances.