[Wien] problem with init_phonon_lapw

[Chandrika]

Dear Dr Blaha,
Thank you for the suggestions. I tried to run it without accepting the
default SGROUP. I gave the following inputs :
1) RMT & number range : 1.6 1-64 (I got RMT 1.6 for vol optimisation)
2) Reduction in % : 5
3) Do you accept these radii : a
4) nn specify : 2.1
5) saved outputnn file shows 24 atoms instead of 64
6) sgroup asks for editing : How do I change it ? I gave option c
7) do you want to use the new structure file : n
8) continue with lstart or edit case1.struct_st file : c
9) Space group changed to 99 (P 4 m m) from 225 Fm-3m

I ran the calculations upto dstart but they do not end (it has been running
for 3 hrs). I am running it on a P IV . Although there are no messages have
I got the inputs right?
Also how do I give the correct input for sgroup?
Thank you very much
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: Monday, August 22, 2005 3:21 PM
Subject: Re: [Wien] problem with init_phonon_lapw


> I don't think there is any problem with your calculations.
>
> Aparently you generated (properly ?) a supercell which consists of 64
atoms.
> Than one atom is displaced and the nn program found out, that even after
> this displacement some of the atoms are still equivalent and wants to
> regroup the 64 atoms into some other set.
>
> I'd assume that everything is ok and you should follow the suggestion of
> init_lapw and accept the new struct_nn file. (Be sure to use the latest
> ini_lapw!)
>
> The only part which could be different from a "normal" setup is that you
> should NOT follow the suggestion of SGROUP, when it changes the
> lattice type (lattice parameters,...), because from this reduced cell
> the analyse_phonon script might not be able to reconstruct the forces
> for all atomes in the original supercell.
>
> > Hello Wien users,
> > I have been trying to resolve a problem with phonon lapw (including
writing to this site). I would much appreciate any suggestions.
> > I have generated a supercell (.d45) file using the software Phonon. The
system is cubic SiC ( supercell contains 64 atoms). The input data used were
the minimum obtained after volume optimisation with Wien2k (a=b=c= 4.129142
Ang). In Phonon I used : No. of non-eq. elastic: 0
> > No. of non-eq. displacive particles : 2
> > Supercell : 2x2x2
> > The .d45 file was then transferred to Wien2k.
> > After running init_phonon_lapw with the options RMT = 1.6 (we got this
RMT after volume optimisation)and atom number range 1-64 we get the error :
> >  Mult not equal Please check outputnn
> > ityp not equal Please check outputnn
> > In output nn file I find that the number of inequivalent atoms has
changed from 64 to 24.
> > Please suggest what I could do
> > Thanks in advance,
> > 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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