[Pw_forum] Silent Calculations

Fri Aug 8 12:49:55 CEST 2008

Dear Eyvaz,

It would be nice if you explain why phonons and shifted k-mesh are
incompatible. Hiowever, I have used shifted k-mesh for phonon calculations
and didn't find anything unusual for the systems I tried so far.

Regards,

Subhradip

> Dear Miguel,
>
> It might be I am wrong, but I am not sure phonons and shifted k-points are
> compatible.
> At least, I never did it (i.e. used only unshifted k-vectors).
>
> As concerns your joke about August, well, it is pretty good. And add
> September, October, November, etc.
> This one recalled me a famous math problem ...
>
> Bests,
> Eyvaz.
>
> -------------------------------------------------------------------
> Prof. Eyvaz Isaev,
> Theoretical Physics Department, Moscow State Institute of Steel & Alloys,
> Russia,
> Department of Physics, Chemistry, and Biology (IFM), Linkoping University,
> Sweden
> Condensed Matter Theory Group, Uppsala University, Sweden
> Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
>
>
> --- On Fri, 8/8/08, Miguel Martínez <miguel.martinez at ehu.es> wrote:
>
>> From: Miguel Martínez <miguel.martinez at ehu.es>
>> Subject: [Pw_forum] Silent Calculations
>> To: "PWscf Forum" <pw_forum at pwscf.org>
>> Date: Friday, August 8, 2008, 1:28 PM
>> 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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>
>
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************************************************************************
              Dr. Subhradip Ghosh
              Assistant Professor
              Department of Physics
            Indian Institute of Technology
               Guwahati,Assam-781039
                    India
               E-mail:subhra at iitg.ernet.in
               Phone: +91 361 2582717(O)
                      +91 361 2584717(R)
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