[Pw_forum] NMR Gipaw Calculations

[Ambrozio]

Dear Davide,

Thanks for replying,

I'm working with systems with more than 100 electrons. The systems have 130
or more carbon atoms, it's expensive to me increase the number of k-points.
I need optimize the computational cost, do you have a hint in this case?

Thanks a lot,


Alan.

2017-09-22 7:15 GMT-03:00 Davide Ceresoli <davide.ceresoli at cnr.it>:

> Dear Alan,
>      I would try to reach an absolute error of the order of
> 0.001 on the f-sum rule, for systems up to ~100 electrons.
> I never investigated whether an absolute or relative error
> is the right choice.
>
> Best regards,
>      Davide
>
>
>
> On 09/21/2017 07:41 PM, Ambrozio wrote:
> > Hi dear users and developers,
> >
> > I have a question regarding the chemical shielding convergence using
> Gipaw. As
> > the best of my knowledge, the f-sum rule parameter is an indicative of
> the
> > convergence, corresponding to the number of valence electrons. I use a
> criterion
> > of 0.01 for the absolute error in the f-sum rule tensor  principal
> components.
> > I'd like to know if this criterion is correct? I mean ... should I take
> the
> > absolute error ? or the relative one?
> >
> > Regards,
> >
> > Alan,
> >
> > Federal University of Espirito Santo, Vitoria, Brazil.
> >
> > --
> >
> > Alan J. Romanel Ambrozio
> > Bacharel em Física
> > Mestre em Eng. de Materiais
> > Doutorando em Física - PPGFis
> >
> >
>
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-- 

Alan J. Romanel Ambrozio
Bacharel em Física
Mestre em Eng. de Materiais
Doutorando em Física - PPGFis
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