After many time, finally I ran some simulations (cluster problems), the 'jumps' in the energy convergence remain, but reducing the k-points and cutoffs, was more fast.
The more fast convergence was (and without many jumps) : -increasing the mixing_beta from 0.1 to 0.3 -NO use local-TF in the mixing_mode -NO change the mixing_ndim -Reduce the vaccum. -Reduce cutoff energy. When I only change the mixing_mode and mixing_beta from this previous data (even reduce from 0.1 to 0.09) the convergence problem remain and increase. I hope that with this, the problem disappear. Probably always was the vaccum, and the default values (except mixing_beta) was fine. After how many SCF cycles these "fluctuations" appear? Usually each 10 steps. Related with 0.1 of mixing_beta?? And thank you very much for all the answers, and any other suggestion is welcome. Best Regards Joaquin On Fri, Sep 3, 2010 at 4:05 AM, Tone Kokalj <tone.kokalj at ijs.si> wrote: > On Thu, 2010-09-02 at 08:38 -0500, joaquin peralta wrote: > > Thanks, i obtain more fast convergence for 1V/A, but ... > > > > If I use the previous results from 1V/A in order to calculate an > > increase in the Field i obtain fluctuation in the energy. > > > > total energy = -261.46819272 Ry > > total energy = -261.46815798 Ry > > total energy = -261.46816720 Ry > > total energy = -261.46260676 Ry > > total energy = -261.37365516 Ry > > total energy = -261.46820680 Ry > > total energy = -261.46821935 Ry > > total energy = -261.46807352 Ry > > total energy = -261.46825528 Ry > > total energy = -261.46820900 Ry > > total energy = -261.46803348 Ry > > > > for my case, is recommendable reduce the precision by default of the > > energy convergence from 1D-4 to 1D-3? > > To what energy threshold are you referring: conv_thr (in &electrons) or > etot_conv_thr (in &control). According to the value of 1d-3/1d-4 I would > assume the latter; note however that the latter has nothing to do with > the SCF convergence, as it is an optimization threshold criteria for > geometry optimizer. > > If you use 1d-4 for the conv_thr, then the value is much too high, it > should be 1d-6 or, even better, lower than that. > > After how many SCF cycles these "fluctuations" appear? > > You may try to reduce mixing_beta to 5%, ... > > The following considerations will speed-up your calculations, hence you > will be able to do more SCF convergence tests: from the previous emails > of yours, I notice that you use over 50 Angs of vacuum, which is HUGE (I > would assume that about 25 Angs should be sufficient; in this case there > will be more than 10 Angs spacing from the slab to the dipole-layer). I > also noticed that ecutwfc/ecutrho of 30/500 ry is a very large number > for Aluminum. > > Regards, Tone > -- > Anton Kokalj > J. Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia > (tel: +386-1-477-3523 // fax:+386-1-477-3822) > > Please, if possible, avoid sending me Word or PowerPoint attachments. > See: http://www.gnu.org/philosophy/no-word-attachments.html > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > -- ---------------------------------------------------- Group of NanoMaterials ---------------------------------------------------- http://www.gnm.cl ---------------------------------------------------- Joaqu?n Andr?s Peralta Camposano ---------------------------------------------------- http://www.lpmd.cl/jperalta In a world without frontiers, who needs Gates and Win. -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20100924/132c0d10/attachment-0001.htm
