As expected, the general trend observed in PIMD simulations is that NQEs tend to soften the structure of liquid water: for BLYP 199 , SCAN/ML , PBE0-D3 151 , SCAN0/ML 161 , RPA/ML 162 and MP2/ML 202 less structured RDFs were found when including NQEs. For other functionals like SCAN 180 , B97M-rV 114 and revPBE0-D3 , O-O RDFs remain almost unchanged, while the O-H and H-H RDFs become less structured. O-H and H-H RDFs are also less structured for BLYP-D3 180 and revPBE-D3 200 , that however have a slight decrease in the O-O first minimum (by ∼0.1) when adding NQEs, with no impact on the first maximum. However, overall NQEs seem to have a marginal influence on the positions of the maxima and minima of the distribution functions. Hence, classical RDFs tend to be either too structured or very similar to their quantum analogues. This is in agreement with experimental isotope studies between heavy and light water that also showed that NQEs soften the structure of liquid water . Hence, NQEs partially explain why in Fig. most DFT functionals tend to overstructure water compared to the experimental results. The gray areas plotted in this figure account for possible deviations due to the neglect of NQEs. These are based on the previously-cited PIMD references, potential discrepancies between experimental measurements , and the variance of the rescaling procedure to 298 K. These areas therefore enclose the most promising XC functionals to be predictive when including NQEs.