Abstract
A diagrammatic expansion for the dynamic exchange-correlation kernel of time-dependent density functional theory is formulated. It is shown that has no singularities at Kohn-Sham transition energies in every order of the perturbation theory. However, it may diverge with the system size in extended systems. This signifies that any approximate perturbative substitute for requires a consistent perturbative treatment of the response function to avoid uncontrollable errors in the many-body corrections to excitations energies.
- Received 10 December 2001
DOI:https://doi.org/10.1103/PhysRevB.65.113107
©2002 American Physical Society