[Pw_forum] i/o question

[Gabriele Sclauzero]

Hi Luke,

Luke Shulenburger wrote:
> Hello,
> 
> I'm using pwscf to generate wavefunctions for quantum Monte Carlo
> calculations and have run into an I/O oddity I wanted to solicit advice
> about.  My calculations proceed as follows:  scf calculation -> nscf
> calculation with specific k-points -> pw2casino for output.  Thinking that
> the nscf calculation would need significantly fewer resources than the
> scf, I used 64 processors for the scf, 16 for the nscf and than 1 for
> pw2casino (I need everything written to a single file at the end).  In
> order for this to work, I specified wf_collect=.true. in both the scf and
> nscf input files.  Both of those tasks completed without incident but
> pw2casino died with an I/O error (unable to read file).

Which file? Can you try to identify the missing file? And which version of QE are you using?


> However, I rerun
> everything using the same number of processors for scf and nscf, and only
> having wf_collect=.true. in the second step, everything runs perfectly.
> 
> Looking into the output directory I notice two things.  When I have
> wf_collect in both files, I still end up with 64 .wfc* files in the
> directory as well as having directories for all of the k-points from the
> scf calculation in the outdir/prefix.save/ directory.  

I don't know if all the *.wfc?? files will be deleted when you specify wf_collect=.TRUE. 
(I guess so, after having a look to PW/stop_run.f90), but you should have the eigenvectors 
(i.e. the wavefunction coefficients) for each k-point stored in the corresponding 
directory as a evc.dat file. Those should be enough to restart/postproc the run (if it 
ended smoothly), since pw2casino (as postproc) uses pw subroutines to read the restart 
files and fill the variables.

GS


> Is it possible this
> is confusing pw2casino?  Is there some way this problem could be remedied
> or am I making some logical mistake with the way I'm attempting to use the
> code?
> 
> Thanks,
> 
> Luke Shulenburger
> Geophysical Laboratory
> Carnegie Institution of Washington
> (lshulenburger at ciw.edu)
> 
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
> 

-- 


o ------------------------------------------------ o
| Gabriele Sclauzero, PhD Student                  |
| c/o:   SISSA & CNR-INFM Democritos,              |
|        via Beirut 2-4, 34014 Trieste (Italy)     |
| email: sclauzer at sissa.it                         |
| phone: +39 040 3787 511                          |
| skype: gurlonotturno                             |
o ------------------------------------------------ o