[Pw_forum] Silent Calculations

[S. K. S.]

 Dear Miguel,

 Yes, you are right. The linear response calculation needs
 much time even for calculating phonons at Gamma point.
 Only for Gamma point phonon  one
 can use "Frozen
 phonon" method because
 it is much faster.

 The calculations can  be got stalled for many reasons.
 You have not mentioned whether at last
 (I mean  staying  in the silence mode for few weeks) your jobs
 properly (without any error) get over or not???

 If  yes, then it can be due to the problem in your
 parallel computer - may be  out  of  16 processors
 some particular processor was  down for some time.

 If  the  answer of  the above question is no,  then  the
 memory of your computer is not sufficient
 enough to tackle a large system with lot of atoms
 because it needs large memory and  as well as
 generates a huge tmp file.

 All  input parameters
 (deguass, la2F, filedvscf ......)  also should be given correctly  for
 electron-phonon calculation.

 regards,
 SKS
 JNCASR
 Bangalore


On 8/8/08, Miguel Martínez <miguel.martinez at ehu.es> wrote:
>
> Dear everybody,
>
> I've been running into a few issues as of late, when running some
> calculations, it seems the calculations have stalled for a pretty long
> period of time.
>
> The one that troubles me less, taking into account that it's pretty
> expensive, is an electron-phonon calculation. This is a pretty large
> system (20 atoms in the primitive cell) and computing the phonons at
> gamma took ages (well two days using 4 processors). It would be great
> if some output were written just to remind you the code is still
> working, maybe something related to convergence. But I find somewhat
> disturbing that no line was written since the electron phonon
> calculation began.
>
> My other issue is a very similar stalling in a Raman calculation. No,
> it's not the same structure. Here, I lack from experience, since this
> is the first Raman calculation I've done outside the examples.
>
> Self-consistent input is:
> &control
>    calculation='scf'
>    restart_mode='from_scratch',
>    prefix='sih4',
>    tstress = .true.
>    tprnfor = .true.
>    pseudo_dir = '/home/wmbmacam/pseudo/',
>    outdir='/scratch/wmbmacam/fdd2-raman/'
> /
> &system
>    ibrav= 10, celldm(1) = 12.65898481, celldm(2) = 1.07100858,
> celldm(3) = 0.621208699, nat=10, ntyp= 2,
>    ecutwfc = 55.0
>    nr1= 72, nr2= 72, nr3= 72
> /
> &electrons
>    conv_thr = 1.0d-8
>    mixing_beta = 0.7
> /
> ATOMIC_SPECIES
> Si  28.0855 Si.pbe-rrkj.UPF
> H   1.0079  H.pbe-vbc.UPF
> ATOMIC_POSITIONS {crystal}
> Si 0.614368447799 0.385631552201 0.614368447799
> Si 0.864368447799 0.635631552201 0.864368447799
> H  0.442372877617 0.836174882136 0.364427192728
> H  0.364427192728 0.357025047520 0.442372877617
> H  0.892974952480 0.885572807272 0.413825117864
> H  0.413825117864 0.807627122383 0.892974952480
> H  0.378768583324 0.338682246661 0.003482898532
> H  0.003482898532 0.279066271483 0.378768583324
> H  0.970933728517 0.246517101468 0.911317753339
> H  0.911317753339 0.871231416676 0.970933728517
> K_POINTS {automatic}
> 12 12 12  1 1 1
>
>
> The phonon input is:
>
> phonons of Sih4 at Gamma
> &inputph
> tr2_ph=1.0d-16,
> prefix='sih4',
> epsil=.true.,
> trans=.true.,
> lraman=.true.,
> elop=.true.,
> amass(1)=28.0855,
> amass(2)=1.00794,
> outdir='/scratch/wmbmacam/fdd2-raman/',
> fildyn='sih4.dynG',
> fildrho='sih4.drho',
> /
> 0.0 0.0 0.0
>
>
> The calculations stalled right after the effective charges calculations.
> After that, it spent 24 hours without writing anything (it needed 10
> hours to compute the effective charges). No convergence, no threshold,
> no crashes, no nothing.
>
> Is this behaviour normal? Or are my compiled binaries just telling me I
> should stop bothering them in August?
>
> Finally, I just wanted to note that the amasses in example 15 are
> seemingly wrong. While the masses in the scf run are fine, the ones
> used in the phonon calculations correspond to GaAs instead of AlAs.
>
> Regards,
>
> Miguel
>
> --
> ----------------------------------------
> Miguel Martínez Canales
>   Dto. Física de la Materia Condensada
>   UPV/EHU
>   Facultad de Ciencia y Tecnología
>   Apdo. 644
>   48080 Bilbao (Spain)
> Fax:  +34 94 601 3500
> Tlf:  +34 94 601 5326
> ----------------------------------------
>
> "If you have an apple and I have an apple and
> we exchange these apples then you and I will
> still each have one apple. But if you have an
> idea and I have an idea and we exchange these
> ideas, then each of us will have two ideas."
>
> George Bernard Shaw
>
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