[Pw_forum] vc-relax

[hania djani-ait aissa]

Dear Axel,
Maybe the ignorance mixed with generosity can lead to great patience...
What do you mean by imbalanced k-point sampling? Running as root user is the bad habit of our Lab. I will try to impose sessions.
If i was a Phd student of you, this woul be a different story :)
thanks for your response,
 
Hania Djani Ait Aissa
PHd student
Algeria> Date: Sat, 24 Jan 2009 12:05:49 -0500> From: akohlmey at cmm.chem.upenn.edu> To: djaithania at hotmail.com> CC: pw_forum at pwscf.org> Subject: Re: [Pw_forum] vc-relax> > On Sat, 24 Jan 2009, hania djani-ait aissa wrote:> > HDA> > HDA> Dear all,> > HDA> i am doing calculation on orthorombic system containing 36 atoms > HDA> (Bi2WO6). My computer is a workstation HP xw6400 quad-core Xeon, > HDA> 2GB. Vc-relax on this system spent more than 01 mounth and still > > congratulations for your patience. i would have thought about > alternate ways bring this to a result long ago.> > HDA> not finish. the energy is converging but forces fluctuate. is there > HDA> something wrong in my input in terms of umass or dt? or have i to > HDA> capitulate to this very slow convergence?> > one thing to consider is the fact, that your oxygen atoms> are over ten times lighter than your other atoms. that means> that the (much) heavier atoms can kick them around good, even> with little movement. for structural relaxation, mass doen't > matter, so i would set all atoms to the same atomic mass.> > HDA> here is the input file. Any suggestions will welcome. > > since you have constrained computational resources, have you> tried running a smaller version of this system first and finding> out the optimal parameters for the cutoffs and convergence thresholds?> > also, it looks like you have imbalanced k-point sampling.> > cheers,> axel.> > HDA> &control calculation = 'vc-relax' restart_mode = 'from_scratch' > HDA>pseudo_dir = '/root/pwscf/pseudo/' outdir = '/root/tmp/' tstress = > > are you running this as root user???? > if yes, be glad you are not a phd student of mine...> > > [...]> > HDA> thanks a lot> HDA> > HDA> Hania Djani-ait aissa> HDA> PHD student> HDA> Algeria> HDA> > HDA> > HDA> _________________________________________________________________> HDA> Sur Windows Live Ideas, découvrez en exclusivité de nouveaux services en ligne... si nouveaux qu'ils ne sont pas encore sortis officiellement sur le marché !> HDA> http://ideas.live.com> > -- > =======================================================================> 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> tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425> =======================================================================> If you make something idiot-proof, the universe creates a better idiot.
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