The ABINIT Users Mailing List ( CLOSED )

[Masayoshi Mikami <mmikami@rc.m-kagaku.co.jp>]

Dear Patrick,

I am afraid that I do not catch your point correctly
by guessing what you are doing from your e-mail ...

As mentioned the Netiquette/FAQ/problem_report_format,
        http://www.abinit.org/community/?text=netiquette
        http://www.abinit.org/about/?text=../Infos/FAQ
        http://www.abinit.org/community/?text=bug_report
could you please describe what you did and what you get
by citing your input files ? (If you would not like to disclose them,
how about substituting znucl parameters with something else ?
(Your problem in this case appears just related to geometry,
 not pseudopotentials, so that disclosing your inputs with such
 "element substitution" would be OK)

In any case, for my cases so far, I often use
 irdwfk 1
 restartxf 1
from the 2nd input.
(here *o_WFK created in the 1st run  is renamed
 as *i_WFK beforehand ...)

Good Luck,
Masayoshi

On 2004/11/24, at 2:29, Patrick Welche wrote:

> I suspect this is a FAQ, but I didn't see any references to the
> problem I see..
>
> Essentially, I try an ionmov 3 optcell 2 calculation for a Cccm 
> (spgroup 66)
> crystal. My original input file just has the natrd 12 attoms in it, 
> with
> a (1,0,0)(0,1,0)(0,0,1) rprim, setting brvltt -1 to find the real 
> rprim.
> I just enter xred for the 12 atoms and let the spgroup find all natom 
> 58.
> (116 in the conventional orthorhombic unit cell)
>
> Time passes and 30 Broyden steps later, I have not converged. So the
> problem now is, how to restart where I stopped? (Maybe increasing ecut
> from 25 to 35 at the same time)
>
> I cut and pasted the acell, rprim, xred, typat from the output file
> back into the input file. As rprim now looks like a real primitive
> unit cell, I thought I would take brvltt -1 out (and of course removed
> natrd 12 as there are 58 atoms listed)
>
> This gave me the error:
>
>  chkprimit : ERROR -
>   According to the symmetry finder, the unit cell is
>   NOT primitive. The multiplicity is  2 .
>   The use of non-primitive unit cells is allowed
>   only when the input variable chkprim is 0.
>   Action : either change your unit cell (rprim or angdeg),
>   or set chkprim to 0.
>
> yet the rprim is essentially
> (sqrt(3)/2,1/2,0),(-sqrt(3)/2,1/2,0)(0,0,1)
> which seems right. For the conventional cell, I would expect 
> multiplicity 2
> as it is C-centered, with 116 atoms.
>
> For no logical reason, I put brvltt -1 back in, and get:
>
>  chkorthsy: ERROR -
>   The symmetry operation number    3 does not preserve
>   vector lengths and angles.
>   The value of the residual is  6.1161E+04.
>   Action : modify rprim, acell and/or symrel so that
>    vector lengths and angles are preserved.
>    Beware, the tolerance on symmetry operations is very small.
>
> So I am confused: the calculation used the symmetry and gave me an 
> output
> file. How come I need to modify the output? (Should I not have picked 
> xred
> but rather xcart or some other version of the coordinates?)
>
> Cheers,
>
> Patrick
>
> P.S.: I use getwfk -1 during the calculation, but then it seems I can't
> make use of the last _WFK file, as apparently at most one of getwfk and
> irdwfk can be non zero. Is there a way of not starting again from a 
> random
> wavefunction?