We found that the meta-GGA functional ωB97MV 56 with VV10 dispersion correction has the best performance and PBE0 is a close second, with less than 25 cm -1 deviations from the CCSD(T) reference (Table ). Because of the relatively low computational cost and relatively high accuracy, we therefore continued using PBE0 in this paper. We used the def2-TZVP 58 electronic basis set for methanol calculations and def2-TZVPPD for water clusters calculations. As for nuclei, we only treated protons quantum mechanically because they feature the most significant nuclear quantum effects, but we note that a full quantum treatment for all nuclei is possible. The PB4D basis set was used for protons.