Spin-flip excited states via ground state density functional theory


  Eli Kraisler [1,2]  ,  Guy Makov [3]  
[1] Raymond and Beverley Sackler Faculty of Exact Sciences, School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978, Israel
[2] Physics Department, NRCN, P.O. Box 9001, Beer Sheva 84190, Israel
[3] Department of Materials Engineering, Ben-Gurion University of the Negev, P.O.Box 653, Beer-Sheva 84105, Israel

The possibility to describe selected excited states of atoms with time-independent ground state density-functional theory (DFT) is examined. Using ground-state DFT calculations, while restricting the spin S of the system, we  obtain excitations which occur via a spin-flip process.  This procedure is analogous to that used to obtain ionization energies by restricting the number of electrons, N. Excitation energies associated with spin-flips are calculated for light atoms within both the local spin-dependent (LSDA) and a gradient-generalized (GGA) approximation. Comparison to experimental spectroscopic results reveals a good correspondence. Therefore, it is reasonable to expect that spin-related excitations in more complex systems (e.g. molecules and clusters) can be described via ground-state DFT.