[Pw_forum] problem in relaxation by using bfgs

[Javad hashemifar]

Many thanks Dr Giannozzi for your kind attention.
I found that if I use bfgs_ndim    = 2  then the mentioned problem
will not appear at all.
If you find any reason behind this error please keep us (users) informed.

Kind regards
Javad Hashemifar

On 1/16/07, Paolo Giannozzi <giannozz at nest.sns.it> wrote:
>
> On Dec 22, 2006, at 9:20 , Javad hashemifar wrote:
>
> > I am trying to relax a tetragonal interface supercell at different
> > values of vertical lattice parameter (celldm(3)). I am using
> > calculation=relax and the namelist IONS is as follows:
> >
> > ion_dynamic = bfgs
> > bfgs_ndim    = 3,
> > pot_extrapolation = "second_order",
> > wfc_extrapolation = "second_order",
> >
> > [...] For some values of celldm(3) every thing is OK and the system
> > relax well and both etot_conv_thr and forc_conv_thr satisfies. But in
> > some other values of celldm(3) the calculation stops with the
> > following error:
> >
> > from checkallsym : error #         1
> > some of the original symmetry operations not satisfied
>
> we tried your test and actually there is a problem, but we don't
> know what the problem is. Could you please verify if the error
> happens also if you remove the line
>     bfgs_ndim    = 3
> ? Paolo
> ---
> Paolo Giannozzi, Democritos and University of Udine, Italy
>
>
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-- 
======================================
Seyed Javad  Hashemifar,    Ph.D.
[current:]
Tel:+49-203-3794743        Fax:+49-203-3794742
Fachbereich Physik (AG Kratzer), Universitat Duisburg-Essen
47048 Dusiburg, Germany
[permanent:]
Tel:  +98-311-3912375       Fax: +98-311-3912376
Physics Department, Isfahan University of Technology
84156 Isfahan, Iran
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