, while the latter case is characteristic for fragments with different ionization energies and large intermolecular separations. As was mentioned above, a description of the radical cation electronic structure in general and prediction of spin-density delocalizations in particular may be problematic with both the KS-DFT and FDE approaches. However, the tendency of FDE to overlocalize charge and spin density can be used to construct an approximate electronic wave function Ψ of the radical cation complex [A • • • B] +• , which provides a qualitatively correct description of the electronic structure. This can be achieved by computing two wave functions Φ 1 and Φ 2 corresponding to the charge-localized states |A +• B and |AB +• and taking the total electronic wave function Ψ as a linear combination,