Figure 2.

¹⁷O MAS NMR spectra of CsH₂PO₄ (a) obtained at 16.4 T with a MAS rate of 20 kHz, and calculated line shapes at 16.4 T, corresponding to different models for the symmetric O3–H2···O3 hydrogen bond, assuming: (b) a centered H2 hydrogen bond (i.e., with H2 equidistant between the two O3 atoms (Figure 1a), (c) the static disorder model (Figure 1b and c), and (d) the dynamic disorder model with a hopping frequency of ≥10⁷ Hz. These simulations were performed with the NMR parameters extracted from the first-principles calculations (Table 1).