Requests for technical support from the VASP group should be posted in the VASP-forum.

Difference between revisions of "ANTIRES"

From Vaspwiki
Jump to navigationJump to search
(Created page with "{{TAGDEF|ANTIRES|0 {{!}} 1 {{!}} 2}} The flag {{TAG|ANTIRES}} determines whether the Tamm-Dancoff approximation is used or not. The allowed settings are: \begin{tabular}{ll}...")
 
Line 4: Line 4:
 
is used or not. The allowed settings are:
 
is used or not. The allowed settings are:
  
 +
{{DEF|ANTIRES|0|if {{TAG|LHFCALC}}{{=}}.TRUE.|0|otherwise}}
 
\begin{tabular}{ll}
 
\begin{tabular}{ll}
 
{\tt ANTIRES}=0 & default: Tamm-Dancoff  approximation (TDA) \\
 
{\tt ANTIRES}=0 & default: Tamm-Dancoff  approximation (TDA) \\

Revision as of 19:33, 13 January 2017

ANTIRES = 0 | 1 | 2 

The flag ANTIRES determines whether the Tamm-Dancoff approximation is used or not. The allowed settings are:

Default: ANTIRES = 0 if LHFCALC=.TRUE.
= 0 otherwise

\begin{tabular}{ll} {\tt ANTIRES}=0 & default: Tamm-Dancoff approximation (TDA) \\ {\tt ANTIRES}=1 & yields exact results at $\omega=0$ at roughly the same cost as TDA \\ {\tt ANTIRES}=2 & beyond Tamm-Dancoff, coupling between positive and negative frequencies \end{tabular}

\noindent VASP uses the procedures outlines in Ref. \cite{Sander15} to include contributions beyond Tamm-Dancoff. Beyond TDA calculations increase the compute time and memory requirements by typically a factor 2.



Contents