Exchange and Correlation Kernels at the Resonance Frequency: Implications for Excitation Energies in Density-Functional Theory

X. Gonze, M. Scheffler
1999 Physical Review Letters  
Specific matrix elements of exchange and correlation kernels in time-dependent density-functional theory are computed. The knowledge of these matrix elements not only constraints approximate time-dependent functionals, but also allows to link different practical approaches to excited states, either based on density-functional theory, or on many-body perturbation theory, despite the approximations that have been performed to derive them.
doi:10.1103/physrevlett.82.4416 fatcat:fz7ck3cdovecddooib5tuj3bye