Samples were ground and loaded into borosilicate capillaries with an inner diameter of 0.78 mm and a height of 3.9 cm before sealing. Total scattering data for PDF analysis were collected at the I15-1 beamline at the Diamond Light Source, UK (experiment EE20038, λ = 0.189578 Å, 65.40 keV). Empty instrument (background) and empty capillary scans were run; all scans were collected over a ∼0.4 < Q < ∼26 Å -1 range. The raw data were processed using GudrunX and over a 0.5 < Q < ∼20 Å -1 range and were corrected for background, container, absorption, multiple and Compton scattering. Fourier transformation of the processed total scattering data yielded real space pair distribution function, G(r). Here we use the D(r) form to accentuate high-r correlations. 31 P NMR spectroscopy. P MAS NMR spectra were collected at 161.97 MHz (magnetic field of 9.4 T) on a Bruker AV-400-WB with a 4 mm triple channel probe with ZrO rotors, Kel-F-plug at room temperature and 10 KHz slew rate. A single π/2 pulse of 60 kHz and spectral width of 100 kHz was used in the direct irradiation tests. The relaxation time was 40 s and samples were accumulated for 128 scans. In the CP-MAS tests a 1H excitation pulse of 3 µs, 3 ms contact time, 100 kHz spectral width, tppm 15 decoupling at 80 kHz were used, and samples accumulated with 512 scans were used. The relaxation time was 5 s. In both cases (NH4)H2PO4 (ADP) at 0.81 ppm was used as secondary reference with respect to H3PO4 85% as the primary reference. The chemical shift resolution was ± 0.2 ppm.