[Pw_forum] Running nscf without altering wfc and charge density files

[Axel Kohlmeyer]

On Mon, 6 Nov 2006 stewart at cnf.cornell.edu wrote:

DS> Hi everyone, 
DS> 
DS> I am setting up a process where I will need to run several nscf calculations 
DS> for band energy values for arbitrary k-points using the wfc and charge 
DS> density from an initial scf calculation.  However, I want to insure that the 
DS> nscf runs do not write over the original wfc and charge density files so I 
DS> can do subsequent nscf calculations.  Is there a way to do this with pwscf?  

hi derek,

it might work, but there is no special flag. you could try making
the restart directory read-only with chmod and then see if pw.x 
still works. i made an audit of file accesses recently (to optimize
i/o buffering on a disk-less machine) and it looks as if there
are less writes now. i didn't try an nscf run, though.

DS> Or do I need to keep a storage directory with the original results and copy 
DS> them over after every run? 

that is the recommended way.

cheers,
   axel.

DS> 
DS> Thanks, 
DS> 
DS> Derek
DS>  
DS> 
DS> ################################
DS> Derek Stewart, Ph. D.
DS> Scientific Computation Associate
DS> 250 Duffield Hall
DS> Cornell Nanoscale Facility (CNF)
DS> Ithaca, NY 14853
DS> stewart (at) cnf.cornell.edu
DS> (607) 255-2856 
DS> 
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DS> 

-- 
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Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
   Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
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