Third, potential reconstruction techniques can be used in cases where the required supermolecular DFT calculation and the corresponding potential reconstruction are not the main computational bottleneck. For instance, an application of potential reconstruction to calculate electronic excitation energies in micro-solvated systems has been presented by our groups in Ref. . By correcting the errors introduced in terms of an approximate NAKP, it could be shown that excitation energies are considerably improved especially for short solute-solvent distances. These uncoupled FDE-TDDFT calculations (see also Section 6.2.2) represent a case in which potential reconstruction can in fact lead to an improved efficiency compared to supersystem Kohn-Sham calculations -despite the necessity to perform a demanding supersystem potential reconstruction. Efficiency is gained if the TDDFT part of the calculation becomes the bottleneck, since the uncoupled FDEu-TDDFT calculations can be performed in a subsystem (monomer) basis. This, together with the fact that low-cost adiabatic local-density approximation (ALDA) kernels are sufficiently accurate in this context, can make the post-SCF part of the calculation very fast compared to the supersystem calculation. Similar efficiency arguments apply if potential reconstruction is combined with WF-in-DFT embedding strategies, which are discussed below in Section 6.6.