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Difference between revisions of "ANTIRES"

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{{DEF|ANTIRES|0|default: Tamm-Dancoff  approximation (TDA)|1|yields exact results at  ω{{=}}1  at roughly the same cost  as TDA|2|beyond Tamm-Dancoff, coupling between positive and negative frequencies}}
 
{{DEF|ANTIRES|0|default: Tamm-Dancoff  approximation (TDA)|1|yields exact results at  ω{{=}}1  at roughly the same cost  as TDA|2|beyond Tamm-Dancoff, coupling between positive and negative frequencies}}
  
\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}
 
  
 
VASP uses the procedures outlined in Ref. \cite{Sander15} to include contributions
 
VASP uses the procedures outlined in Ref. \cite{Sander15} to include contributions

Revision as of 11:08, 14 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 default: Tamm-Dancoff approximation (TDA)
= 1 yields exact results at ω=1 at roughly the same cost as TDA
= 2 beyond Tamm-Dancoff, coupling between positive and negative frequencies


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



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