Table compares some important structure parameters of the DFT-optimised structures to those of the experimental structure. The cell parameter a is 1.8%/1.0% (PBE-D3/rev-vdW-DF2) larger than the experimental one. This tendency is unsurprising when considering, first, that cell parameters of guest-free zeolites/zeotypes are often larger than those of assynthesised systems and, second, that a tendency to overestimate the cell parameters has been established for both functionals (although it is less pronounced than for many other dispersion-corrected DFT approaches). Regarding bond distances, it is noteworthy that the average Ga-O and P-O bond distances in the DFT-optimised structures are about 0.04 Å longer than in the experimental structure, regardless of the choice of functional. Nevertheless, they fall well into the range of typical Ga-O/P-O bond distances compiled in a survey of experimental zeolite and zeotype structures. Compared to bonds within Ga-O-P linkages, bonds to the oxygen atom of the hydroxyl group are somewhat compressed for gallium, but expanded for phosphorus. The O-H distances amount to 0.971/0.974 Å (PBE-D3/rev-vdW-DF2) for the (Ga-)O-H group and 0.974/0.977 Å for the (P-)O-H group. As the hydrogen atoms were placed on a mirror plane in the starting structure in order to retain the 𝐹𝑚3 𝑐 symmetry, it has to be conceded that the final, optimised positions are likely to depend on the starting positions and may not correspond to global minima. However, it is not expected that the exact orientation of the hydroxyl groups would strongly affect the properties computed using such a DFT-optimised model, e.g., in adsorption simulations.