While some methods based on the adiabatic-connection fluctuation-dissipation theorem are computationally expensive, this is not at all true for functionals within the RPA or for σfunctionals. These are typically evaluated in a post-SCF way, ide-ally using orbitals and eigenvalues from hybrid DFT methods. In this case, the post-SCF calculation of the total energy using the RPA or the σ -functional requires only a fraction of the computational time of the preceding hybrid calculation and thus can be easily carried out routinely.