Notably, as for water-facing segments (Fig. ), also in tails the S CH change only at < 20 w/l in simulations, but in experiments already at > 20 w/l (Fig. ). This delayed response complicates somewhat the general trend presented by the previous paragraph and-especially when combined with slight deviations from experiments in full-to-lowest-hydration S CH magnitude changes seen in all DMPC (underestimation, except in sn-2 carbon 2, see Fig. ), some unsaturated POPC (underestimation, Fig. ), and in several saturated POPC (overestimation, Fig. ) tail segments-leads to situations where certain carbon segments become equally well or better described by CHARMM36 at some hydrations. See, e.g., the DMPC carbon segment 13/13' in Fig. . Forking is in simulations observed in four tail carbon segments (2, 2', 3, and 3') but experimentally only in segment 2 (Fig. ). For segments 3/3', the experimental resolution is not sufficient to judge the correctness of the simulational forking. For segment 2', however, it is clearly too large: Were the simulational value correct, the 2' forking would be also experimentally observable in R-PDLF-as the equally large forking at segment 2 is, see Fig. .