Hi Roberto, a few things that might help
- different starting magnetization (if spin-polarized), e.g. a starting magnetization of 0.4 could lead to a converged value of 0.7 but starting from 0.7 might fail - different surface-atom hubbard_U values: I played a bit with the linear response formalism to determine Hubbard_U values and atoms on surfaces seems to have a different response to hubbard_alpha - dipfield (or related corrections using assume_isolated) - sometimes it just takes very long electron_maxstep~300-500 if you have an input file I would be happy to try it a bit myself, these "convergence problems" are very interesting to play with and overcome! HTH! Chris On Sun, Jul 1, 2018 at 7:00 PM, <[email protected]> wrote: > Send users mailing list submissions to > [email protected] > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.quantum-espresso.org/mailman/listinfo/users > or, via email, send a message with subject or body 'help' to > [email protected] > > You can reach the person managing the list at > [email protected] > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of users digest..." > > > Today's Topics: > > 1. DFT+U and surfaces -- convergence (Roberto Gomes de Aguiar Veiga) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sat, 30 Jun 2018 11:28:07 -0300 > From: Roberto Gomes de Aguiar Veiga <[email protected]> > To: [email protected] > Subject: [QE-users] DFT+U and surfaces -- convergence > Message-ID: <[email protected]> > Content-Type: text/plain; charset="us-ascii" > > > > Dear Espresso users, > > my question is not related to any specific system, since it always > happened to all of them. When I perform DFT+U calculations for bulk > systems (e.g., NiO, Fe2O3, YIG, etc), they usually converge very > quickly. However, when I try to perform calculations for the > corresponding surfaces, they do not converge. I've been using > mixing_mode='local-TF' and descreasing mixing_beta to values as low as > 0.05 for the surface calculations, with no success. Can any of you with > experience in this kind of simulation (DFT+U and surfaces) share what > you usually do to have converged calculations? > > Best regards, > > Roberto > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://lists.quantum-espresso.org/pipermail/users/ > attachments/20180630/7a3dd262/attachment-0001.html> > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > users mailing list > [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users > > ------------------------------ > > End of users Digest, Vol 132, Issue 1 > ************************************* > -- Postdoctoral Researcher Center for Quantum Nanoscience, Institute for Basic Science Ewha Womans University, Seoul, South Korea
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