In order to provide EFG tensors for the three different nuclei, Li, allows for 6 symmetry-inequivalent crystal structures to be enumerated. By 'rattling' the atomic positions using a random displacement procedure and by rescaling the crystalline lattice vectors, a total of 1640 structures are generated that we describe in further detail in the supplementary information (SI). The configurational sampling, rattling, and scaling procedure effectively distributes the interatomic distances across a wide range of 1-2 Å around the mean neighbor distance for every atom combination, as shown in Fig. . The resulting diverse quadrupolar coupling constants C Q and quadrupolar asymmetries η, as calculated from the eigenvalues of the EFG tensors, are shown across the entire database for each nucleus in Fig. . Being only the second ever EFG tensor database available in literature, this heterogeneity of the LTO-EFG database renders it a truly challenging benchmark for ML tensorial learning. descriptor to encode the local atomic environments in a symmetry-invariant way. SOAP is an appropriate special case of the atomic cluster expansion which combines both radial and spherical harmonic basis functions using a Gaussian smearing to approximate the local atomic density ρ(r) in a sphere of radius r c around any atom of a given structure as depicted in Fig. .