Fast regime. We use direct MLFF molecular dynamics to capture fast processes. The final spectrum, Fig. , is obtained by point wise averaging of the individual DFT shielding tensors across 18 samples of the trajectory. For the MFU-4l MOF we sample along a 2 ns trajectory, thus any motion observed is in the fast exchange regime (k ≥ 500 MHz). The MD reveals a well defined asymmetric carbonyl 'seesaw' motion (Fig. , step 2). Notably, the hydroxyl proton was not seen to move significantly leading to two chemically distinct carbonyl sites, one proximal to the proton (Fig. -red) and one distal to the proton (Fig. ). This 'seesaw' motion was found to be asymmetric at a ratio of 83 : 17 in favour of the distal carbonyl being bound to the Zn (Fig. ). This is hypothesised to be due to a weak interaction between the proximal carbonyl and the hydroxyl proton, with the resulting polarisation leading to a reduction in relative binding strength to the Zn. Compared to the slow regime, there is marked narrowing of all three environments as would be expected from the partial motional averaging of the quadrupolar interaction. The hydroxyl peak (Fig. ) now matches well in shape to the experimental spectrum with only a ∆δ obs ≈ 5 ppm discrepancy compared to experiment. However, the distinct proximal and distal carbonyl environments are still well resolved and require further consideration.