The calculation of Al NMR parameters was performed using the Zeroth-Order Regular Approximation (ZORA) Hamiltonian at the scalar (spin-free) level, as implemented in the ADF program package (version 2019). The CQ and η parameters (the whole molecule was used) were calculated by the PBE0 functional, the TZ2P basis set (the QZ4P basis set for the Al atom) and the COSMO solvent model of THF. The chemical shielding (the central part of the molecule was used) was calculated using the PBE0 functional, the QZ4P basis set and the COSMO (THF). The calculated chemical shifts were referenced relative to the experimental chemical shift of solid AlCl 3 as a secondary reference (δ ref = -1.6 ppm) 7 and they are reported relative to AlCl 3 in D 2 O (primary reference). The Euler angles (α, β, γ) were extracted from ADF output files using the program INFOR. The full list of the calculated spectroscopic parameters is available in the Supporting Information (Section S4).