(2.3.1) Helgaker : Pure (non-Kohn-Sham) DFT provides the ground-state density and the ground-state energy. We can then (in principle) obtain rigorously all properties that can be expressed as functions of the density and the energy -for example, derivatives of the energy with respect to nuclear displacements or nuclear magnetic moments (provided DFT has been extended to deal with magnetism as discussed in contribution (4.3.1)). We can in principle also calculate excitation energies, from equiensembles.