[Octopus-users] suzuki_trotter

[Alberto Castro]

Hi Myrta,

You are absolutely right, that error message will always appear, no
matter if you have compiled the code with FFT support or not (in fact
now the code always has to be compiled with FFT support). It is a bug,
and it is not only in 3.0.1, but also in trunk.

Since nobody uses the splitting techniques, it seems that currently
they don't work anyways. In particular the computation of the
non-local pseudopotential components seem to be broken. So I am afraid
you should not use those propagators for the moment.

Cheers,

Alberto.


On Wed, 10 Dec 2008, Myrta Gruning wrote:

> Dear all,
>
> I was trying to run td evolution with the suzuki trotter method 
> (TDEvolutionMethod = suzuki_trotter
> TDExponentialMethod = suzuki_trotter
> in the inp file)
>
> and I got as message:
>
> **************************** FATAL ERROR *****************************
> *** Fatal Error (description follows)
> *--------------------------------------------------------------------
> * You cannnot use the split operator evolution method, or the
> * Suzuki-Trotter, if the code was compiled without FFTW support.
> **********************************************************************
>
> However I do enable the fftw support when configuring and from the
> config.log I can see the libraries were found and the conftest
> successful 
>
> Grepping the source (3.0.1) I found indeed in src/td/td_rti.F90
> (L259-262, subroutine td_rti_init)
> =========
> if(tr%method .eq. SPLIT_OPERATOR .or. tr%method .eq. SUZUKI_TROTTER)
> then
>      message(1) = "You cannnot use the split operator evolution method,
> or the"
>      message(2) = "Suzuki-Trotter, if the code was compiled without
> FFTW support."
>      call write_fatal(2)
>    end if
> =========
>
> However it does not seem to be included in any #ifdef compiler option 
> and for what I can see the program will always return this error message
> regardless of the fftw support.
>
> Is there any particular reason to disable these options or can I
> "safely" comment out those lines and run with Suzuki Trotter?
>
> Thank you in advance,
>
> m
>
>
>
> -- 
>
> ___________________________________
> dr. Gruning Myrta
> Universit? catholique de Louvain
> SE/FSA/MAPR/PCPM
> Croix du Sud,1
> 1348 Louvain-la-Neuve
>
> e-mail: myrta.gruning at uclouvain.be
> phone1:  +32 (0)10 478721
> phone2:  +32 (0)10 478681 
> fax:    +32 (0)10 473452
> URL:    http://www.myrta.eu/
> ___________________________________
>
> _______________________________________________
> Octopus-users mailing list
> Octopus-users at tddft.org
> http://www.tddft.org/mailman/listinfo/octopus-users

======================================================================
Dr. Alberto Castro

Institut fur Theoretisch Physik, Freie Universitat Berlin.
Arnimallee, 14, Berlin 14195 (Deutschland)

Tel:   +49 30 83853028
Fax:   +49 30 83855258
skype: alberto_c_barrigon
email: alberto at physik.fu-berlin.de
======================================================================