[Pw_forum] error: nc already filled

CLAUDIA BUNGARO bungaro at physics.rutgers.edu
Mon Feb 10 17:55:03 CET 2003


Another possible source of error:
in order to compute the real space IFC
you need to compute  the dynamical matrices only on the
q-points which belong to the irreducible wedge of the
crystal.

If you have done this already you can ignore this email.

There is not yet a separate q-point mesh generator, but
if you want you can use pw.x to generate a non-shifted
k-point grid specifying the automatic generation of k-points
seeting in pw.in
 nks=0
and
nk1,nk2,nk3, k1,k2,k3
4 4 4  0 0 0

you will find the k-pints in the irreducible wedge of the
crystal in the standard output file of pw.x

the nr1, nr2, and nr3 in q2r.in are equal to nk1,nk2,nk3.

Claudia

__________________________________________________
Claudia Bungaro
Dept. of Physics and Astronomy, Rutgers University
136 Frelinghuysen Road, Piscataway,  NJ 08854-8019

tel: +1 732 445 4197          fax: +1 732 445 4343
email: bungaro at physics.rutgers.edu
__________________________________________________


On Mon, 10 Feb 2003, Jorge Mario Osorio [iso-8859-1] Guillén wrote:

> Hej,
>
> In fact, I used a small fortran program to generate the q-point grid.
> The inputs are the reciprocal axes (cart. coord. in units 2 pi/a_0)  and
> nr1, nr2, nr3.   I used  nr1=4, nr2=4, nr3=4 to generate q-points and
> in the q2r.inp file as well.  So, I guess it is not the problem.
>
> But, if someone want to exchange with me a q-points generator program in
> order to compare the grid that I have and to allow me to check that my
> troubles are not coming from this.  Also, other possible sources of this
> problem that I can check are welcome.
>
> With best,
>
> Jorge
>
>
>
> Paolo Giannozzi wrote:
>
> > Hi
> >
> > > I guess there was some error during nscf calculations.
> >
> > unlikely
> >
> > > another reason for this could be the use of
> > > different basis vectors (or symmetry) for phonon and
> > > q2r programs.
> >
> > as above
> >
> > > Please check also nr1, nr2, and nr3  in your q2r.in file.
> >
> > I vote for this.  The q2r code does not check if you provided
> > the right values for nr1, nr2, nr3 (there is no simple way
> > to implement this) and it does not even check if you provided
> > any value at all. In the latter case, unpredictable behaviour
> > may follow. From the error message, it looks like
> > nr1=nr2=nr3=0 .
> >
> > > They should be the same for q-points generation.
> >
> > exactly: I guess 4, 4, 4, in this case
> >
> > Paolo
> >
> > --
> > Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
> > Scuola Normale Superiore    Phone:   +39/050509412
> > Piazza dei Cavalieri 7      Fax:     +39/050509417, 050563513
> > I-56126 Pisa, Italy         Office:  Lab. NEST, Via della Faggiola 19
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
>
> --
> Jorge Mario Osorio Guillen   |Telephone: (46-018)-471 35 67
> Condensed Matter Theory Group|Fax: (46-018)-471 35 24
> Department of Physics        |e-mail: Jorge.Osorio at fysik.uu.se
> Uppsala University           |www.fysik4.fysik.uu.se
> Box 530                      |
> SE-751 21 Uppsala-Sweden     |
>
>
>



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