ANTIRES: Difference between revisions
No edit summary |
No edit summary |
||
| Line 16: | Line 16: | ||
{{TAG|BSE calculations}} | {{TAG|BSE calculations}} | ||
{{sc|ANTIRES|Examples|Examples that use this tag}} | |||
{{ | |||
== References == | == References == | ||
Revision as of 14:37, 17 March 2017
ANTIRES = 0 | 1 | 2
Default: ANTIRES = 0
Description: The flag ANTIRES determines whether the Tamm-Dancoff approximation is used or not.
- ANTIRES=0 Tamm-Dancoff approximation (TDA)
- ANTIRES=1 yields exact results at ω=0 at roughly the same cost as TDA
- ANTIRES=2 beyond Tamm-Dancoff, coupling between positive and negative frequencies
VASP uses the procedures outlined in reference [1] to include contributions beyond Tamm-Dancoff. Beyond TDA calculations increase the computational time and memory requirements by typically a factor of 2.