ANTIRES: Difference between revisions

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*{{TAG|ANTIRES}}=0 Tamm-Dancoff  approximation (TDA)
*{{TAG|ANTIRES}}=0 Tamm-Dancoff  approximation (TDA)
*{{TAG|ANTIRES}}=1 yields exact results at  ω{{=}}1   at roughly the same cost  as TDA
*{{TAG|ANTIRES}}=1 yields exact results at  ω{{=}}0   at roughly the same cost  as TDA
*{{TAG|ANTIRES}}=2 beyond Tamm-Dancoff, coupling between positive and negative frequencies
*{{TAG|ANTIRES}}=2 beyond Tamm-Dancoff, coupling between positive and negative frequencies



Revision as of 14:13, 14 January 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 Ref. [1] to include contributions beyond Tamm-Dancoff. Beyond TDA calculations increase the computational time and memory requirements by typically a factor of 2.

References


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