A close inspection of the individual submissions showed that a few submissions made in fact use of the wrong organic molecule. We will mention this in the text. Of less concern was the computation of different minima. The most problematic system in this respect was PCD, with two alcohol groups. Otherwise, only small deviations were observed. It was commonly found in the TPH and FAH geometries that the water molecule was binding out of plane, breaking C s symmetry. This seems to have a minimal impact on the predicted wavenumbers. Independent calculations were carried out at the CCSD(T)/aug-cc-pVTZ level of theory, confirming that the global minimum for both complexes should localise the water molecule in plane.