(3.2.4) Calaminici : The accuracies of static Kohn-Sham DFT dipole polarizabilities are usually in the range of 1%. However, the errors in dynamic dipole polarizabilities can be catastrophic -in particular, for planar conjugated systems. Here, the longrange behaviour of the functional used is critical. The polarizabilities of small metal clusters can be significantly influenced by temperature effects. Furthermore, the experimental references for static polarizabilities of such clusters are not always reliable. In particular, this is the case for the available measured copper-cluster polarizabilities in the literature.