[Pw_forum] Silent Calculations

Miguel Martínez miguel.martinez at ehu.es
Fri Aug 8 11:28:26 CEST 2008

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:
    tstress = .true.
    tprnfor = .true.
    pseudo_dir = '/home/wmbmacam/pseudo/',
    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
    conv_thr = 1.0d-8
    mixing_beta = 0.7
 Si  28.0855 Si.pbe-rrkj.UPF
  H   1.0079  H.pbe-vbc.UPF
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
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.



Miguel Martínez Canales
   Dto. Física de la Materia Condensada
   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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