And I venture an educated guess here, but looks toMe that you could save yourself a lot of time and effort with a small number of well picked single point calculations and thus obtained a much better initialnguess. For your system it should be easy enough to pick a cell that is a bit too large and a bit too small and a few in between.
Variable cell calculation far from equilibrium always converge very slow. Axel -- Dr. Axel Kohlmeyer akohlmey at gmail.com http://goo.gl/1wk0 International Centre for Theoretical Physics, Trieste. Italy. -----Original Message----- From: Alexey Akimov <aaki...@z.rochester.edu> Sender: pw_forum-bounces at pwscf.org Date: Sun, 23 Sep 2012 22:14:14 To: PWSCF Forum<pw_forum at pwscf.org> Reply-To: PWSCF Forum <pw_forum at pwscf.org> Subject: Re: [Pw_forum] Error in routine scale_h (1) I see. Thank you for the explanation! Alexey ----- Original Message ----- From: "Stefano de Gironcoli" <degir...@sissa.it> To: "pw forum" <pw_forum at pwscf.org> Sent: Sunday, September 23, 2012 2:58:47 PM Subject: Re: [Pw_forum] Error in routine scale_h (1) as your cell shrinks the energy cutoff corresponding to your set of plane wave increases and it this exceeds a the maximum values in the precalculated psedopotential table (some 20% higher than the specified ecut by default if i remember correctly) the code stops. You can increase this limit with the cell_factor variable. However if this keeps happening it means that your cell was way too large ! stefano On 09/23/2012 11:42 PM, Alexey Akimov wrote: > my unit cell is not oscillating, but rather shrinking. shouldn't the basis > size (number of plane waves) be bigger for larger cell, so the bigger cell > would determine the maximal amount of memory for simulation even if the cell > contracts? > > ----- Original Message ----- > From: "Paolo Giannozzi" <giannozz at democritos.it> > To: "PWSCF Forum" <pw_forum at pwscf.org> > Sent: Sunday, September 23, 2012 1:19:05 PM > Subject: Re: [Pw_forum] Error in routine scale_h (1) > > > On Sep 23, 2012, at 16:43 , Alexey Akimov wrote: > >> If i restart the calculations with the latest (most optimal) >> configuration of the system and the same amount of memory >> allocated, the further optimization can proceed some more time >> (also ~50 - 70 steps) before next crash. > this should not happen, unless your optimization procedure keeps > oscillating between large and > small volumes. > > P. > --- > Paolo Giannozzi, Dept of Chemistry&Physics&Environment, > Univ. Udine, via delle Scienze 208, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > > > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum -- Dr. Alexey V. Akimov Postdoctoral Research Associate Department of Chemistry University of Rochester aakimov at z.rochester.edu _______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum
