Abstract
An approximate solution to the time-dependent density-functional theory response equations for finite systems is developed, yielding corrections to the single-pole approximation. These explain why allowed Kohn-Sham transition frequencies and oscillator strengths are usually good approximations to the true values, and why sometimes they are not. The approximation yields simple expressions for Görling-Levy perturbation theory results, and a method for estimating expectation values of the unknown exchange-correlation kernel.
| Original language | American English |
|---|---|
| Pages (from-to) | 4 |
| Number of pages | 1 |
| Journal | Physical Review Letters |
| Volume | 90 |
| Issue number | 4 |
| DOIs | |
| State | Published - 2003 |
| Externally published | Yes |