@article{Bacalis_2008, title={Variational functionals for excited states}, archiveLocation={Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο}, url={https://hdl.handle.net/10442/7529}, abstractNote={Functionals that have local minima at the excited states of a non degenerate Hamiltonian are presented. Then, improved mutually orthogonal approximants of the ground and the first excited state are reported.}, author={Bacalis, Naoum C.}, year={2008} }