Pros and Cons of the DFT

• It is computationally very ``cheap''.
• Stablished exchanged functinals are ``good''.
• There is no systematic way to imporve the functionals.
• Dispersion of electrons in not included in the functionals.
• Exchange functionals do not cancel the self-interaction properly.
• If one plugged the density for an excited state, would the same functional give the right energy?