The calculation of the 19 F magnetic shielding tensors for TiF 4 was performed using the GIPAW approach within VASP . The TiF 4 input structure for these reference magnetic shielding calculations was obtained from a geometry optimisation performed in VASP , where only atomic coordinates were relaxed, keeping the cell parameters fixed to experimental values). This geometry optimisation used Ti [Ne] and F [He] pseudopotentials and the Perdew-Burke-Ernzerhof (PBE) GGA functional, augmented with the DFT-D3 correction of Grimme et al. to account for dispersion interactions between the isolated columns of corner-linked TiF 6 octahedra that comprise the TiF 4 structure . Both the geometry optimisation calculation and the subsequent 19 F NMR calculation used a plane-wave cutoff of 550 eV and a 1 × 6 × 3 Monkhorst-Pack k-point grid.