Fig. shows the linear evolution of Eads as a function of εd, revealing that such a descriptor works rather well for close-packed crystallographic structures, this is, fcc and hcp, with R values of 0.916 and 0.952, respectively. However, the adequacy is lower for bcc TMs, with an R of 0.663. Clearly, crystal packing is a factor, but also the stacking, since the trends captured for fcc and hcp are different. The worse performance on bcc can be attributed to DFT lower accuracy on describing virtual orbitals or bands, whose weight is more important on early TMs εd estimates, exactly where bcc TMs are placed.