[CPMD-list] Ag PP

[Ari P Seitsonen]

Dear Alexander,

  How many silver atoms do you now have in your system? Like Axel wrote it 
might be that there are so many states close to the Fermi energy - ehmm, 
better said that there might be many occupied and unoccupied states 
closeby, and during the optimisation they change the ordering. If you are 
sure that there is a gap (e.g. you have calculated the same system with a 
cluster code) there might be some parameters which could help, otherwise 
you might want to switch to fractional occupation numbers (FREE ENERGY 
FUNCTIONAL) and a broadening of the occupation numbers.

  Just a thought...

    Greetings from Karelia/Finland and Zurich,

       apsi

PS Just a detail, do you use the s or p as the local component of the 
  pseudo? And how high is the total energy at the first step?

-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
 Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
 Tel +41 1 635 44 97 / Fax +41 1 635 68 38 / GSM +41 79 719 09 35      
 Anschrift: Physikalisch Chemisches Institut (PCI), Universität Zürich (UniZh)
 Indirizzo: Winterthurerstraße 190, CH-8057 Zürich
 Address:   Schweiz / Svizzera / Suisse / Svizra / Switzerland

On Sat, 22 May 2004, Alexander Martins Silva wrote:

>        Hi,
> 
>           I'm using a blyp PP from a colleague of this list ( ...Please, 
> forgive me, I have deleted your email accidentally... Did you have these 
> same problems? ...), and I've realized a little improvement, but there 
> is oscilations and the excessive number of iteractions in the 
> wavefunction optimization yet. As suggested for you, I change the 
> minimizer from ODIIS to PCG, and with this approach the oscillations 
> have finished, but the convergence stils slow:
> ...
> 
>  407  1.293E-03   5.452E-05    -131.750308   -2.013E-05     54.93
> 
>  LINE SEARCH : LAMBDA=.176           ENERGY =          -131.75035
> 
>  408  1.302E-03   5.516E-05    -131.750328   -2.013E-05     55.04
> 
>  LINE SEARCH : LAMBDA=.165           ENERGY =          -131.75037
> 
>  409  1.150E-03   5.651E-05    -131.750350   -2.155E-05     54.81
> 
>  LINE SEARCH : LAMBDA=.171           ENERGY =          -131.75039
> 
>  410  1.486E-03   5.603E-05    -131.750371   -2.137E-05     54.76
> 
>  LINE SEARCH : LAMBDA=.172           ENERGY =          -131.75041
> ...
> 
> 
>        What others parameters should I change to resolve this problem?  
> Another question: Is there another code for TM pseudopotentials besides 
> the Gianozzi's one? 
> 
>       Alexander.
> 
>        Thanks,
> 
>           Alexander.
> 
> 
> Axel Kohlmeyer wrote:
> 
> >On Fri, 21 May 2004, alex.msilva wrote:
> >
> >AM> Hi,
> >
> >hello alexander,
> >
> >AM> 
> >AM>    I´m trying to obtain some results for a 
> >AM> little Ag cluster, so I must to generate a PP 
> >AM> for this atom, using the Gianozzi´s code. After 
> >AM> that, I have done some tests to validate this 
> >AM> PP. I found that a simple optimization 
> >AM> wavefunction calculation were evaluated after a 
> >AM> slow convergence of more than 100 steps. Is this 
> >AM> wrong? What can I do to improve this PP?
> >
> >i have noticed, that systems containing transition
> >metal atoms frequently have convergence issues,
> >especially for larger systems.
> >
> >you may want to try PCG MINIMZE instead of the
> >default ODIIS minimizer. also sometimes the 
> >convergence improves with increasing the cutoff
> >a bit.
> >
> >as for the quality of your pseudopotential,
> >there are two Ag pseudos (one with 1 valence electron
> >and one with 11 valence electrons) in the 
> >goedecker-hartwigsen pseudopotential library for LDA.
> >if your pseudo is using LDA, or you recreate it
> >for LDA, you could compare your results.
> >
> >hope this helps,
> >	axel.
> >
> >AM> 
> >AM> 
> >AM> Alexander.
> >AM>  
> >AM> __________________________________________________________________________
> >AM> Acabe com aquelas janelinhas que pulam na sua tela.
> >AM> AntiPop-up UOL - É grátis!
> >AM> http://antipopup.uol.com.br/
> >AM> 
> >AM> 
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> >
> >  
> >
> 
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