We can yet consider it as a nanocluster. Since its spectroscopic signature is mainly characterized by an intense and narrow plasmon-like absorption band in the 2 to 6 eV region, it is particularly well adapted to test the accuracy of a computational approach since it localizes the plasmon excitation. This singularity comes from its highly symmetric structure which induces a three-time degeneracy of the electronic transition. It is however worth to note that such a highly symmetric nanocluster is not representative of experimental observations. At first glance, we observe that the shape of the spectrum is strongly influenced by the rank of the exchange-correlation approximation. The PBE semilocal density functional provides indeed a multiband absorption spectrum with an absorbance which continuously increases with the excitation energy. Along the 2 to 6 eV region, the superatomic character and collectivity indexes remain nevertheless very low. This diagnostic proves that the contribution of the 5s and 5p shells into the excitations is rather small in comparison to the more inner ones. They can be thus categorized as interband excitations, i.e., excitations taking place from the 4d atomic orbitals to the conduction band of the noble metal. It results that the PBE semilocal approximation overexpresses the contribution of the valence orbitals into excitations just as it is used to overdelocalize the density over the whole system due to the delocalization error.