A possible explanation for the spectral differences observed between semilocal and globalhybrid approximations can be found in Table . It reports the energy levels of the valence orbitals of silver derived from a natural bond orbital (NBO) analysis. We observe that by increasing the fraction of EXX from 0 to 25% (33%), the 4d-5s energy gap increases from 2.61 to 3.84 (4.26) eV. With PBE (0% of EXX), the close proximity of the 4d and 5s energy levels results into a contamination of the expansion of the excited-state wavefunction by 4d orbitals, which thus reinforces the interband character of the excitation, and decreases its plasmon-like character. In this context, the DFT+U approach 93 could be considered as a possible correction to not fully discard semilocal approximations, provided of course that the optimal Hubbard parameter is determined a priori. Global hybrids (EXX larger than 0%) remains however a preferred approach to avoid a 4d contamination of the plasmon-like excitations.