[Wien] error in init phonon lapw calculations with 3x3x3 supercell

[Chandrika]

Dear Dr Blaha,
Thank you very much for the suggestions.
Regards,
Chandrika
----- Original Message ----- 
From: "Peter Blaha" <pblaha at theochem.tuwien.ac.at>
To: "A Mailing list for WIEN2k users" <wien at zeus.theochem.tuwien.ac.at>
Sent: Saturday, August 05, 2006 12:39 PM
Subject: Re: [Wien] error in init phonon lapw calculations with 3x3x3
supercell


> a) You cannot run supercells with 216 atoms on a single PIV with 2 GB
> memory.
> b) rkmax=3.7 would give a very bad calculation
> c) you don't need 2 k-point for such large supercells.
> d) Unless you are searching for some particular feature in the
> phonon-dispersion, you don't need such large supercells for phonons! It is
much
> more important that you use a good RKMAX to get good forces.
>
> > Hello Wien users,
> > I am working with a SiC supercell (3 X 3 X 3)constructed with 'Phonon'.
After I transferred the .d45 file to Wien and ran init_phonon_lapw I get an
error message after dstart that says
> >
> > fortrl : severe (41): insufficient virtual memory.
> >
> > The super cell has 216 atoms.
> > RMT*Kmax = 3.7;
> > RMT =1.76;
> > k points =2
> > plane waves generated = 711879.
> > My system is P IV,  has 2GB RAM and a swap space of 5000 MB. Stack size
unlimit has also been done.
> > Calculations with a smaller supercell (2 X 2 X 2) works fine.
> > Any suggestions on how to resolve this problem will be most appreciated.
> > Thank you for your help.
> > Chandrika
> >
>
>
>                                       P.Blaha
> --------------------------------------------------------------------------
> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
> Email: blaha at theochem.tuwien.ac.at    WWW:
http://info.tuwien.ac.at/theochem/
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