If you obtain a minimum, then you do not have convergence. I think that you have "convergence" when you obtain a plateau. The "" is because you have obtain convergence for that specific parameter (i.e. total energy), but you can not be 100% sure that other parameters are converged too. To be sure, you should repeat the convergence study for each parameter you are interested in, then you can choose the greater value for which ALL convergences are obtained.
Regards, []'s, @mps On Wed, Aug 12, 2015 at 1:53 PM, Ludwig, Stephan < [email protected]> wrote: > Hi, > > I'm pretty sure that this is not a good idea. Your suggestion is just > usable for bond-length... > > > Regards > > -----Original message----- > *From:* Mayuri Vaghela <[email protected]> > *Sent:* Wednesday 12th August 2015 12:13 > *To:* [email protected] > *Subject:* Re: [SIESTA-L] When is convergence reached? > > when you take any convergence if you draw mesh-cutoff vs energy graph , > you will get minima in the graph put that value of meshcutoff as your > converged mesh cut off value > > On Tue, Aug 11, 2015 at 10:21 PM, <[email protected]> wrote: > >> Hi Stephan, >> it depends on how big is your unit cell and what you want to study. >> >> > Hi, >> > >> > I've a question concerning the convergence criterion. >> > >> > Let's say I want to examine convergence of the total energy a system >> with >> > respect to the meshcutoff. >> > >> > When is convergence reached? Is it reached when there is no change in >> the >> > first digit after the comma >> > >> > like in the following example: >> > >> > meshcutoff total energy >> > >> > 150 -42994.1019 >> > >> > 170 -42994.116 >> > >> > 190 -42994.127 >> > >> > 210 -42994.133 >> > >> > >> > >> > or is it usefull to continue the test till there is no change in the >> > second digit after the comma? >> > >> > What is a sensible criterion for convergence? >> > >> > >> > >> > Thanks and regards >> > >> > >> > >> > Stephan Ludwig >> > >> > >> >> >> ********************************************************* >> Dr Zacharias G. Fthenakis >> Research Associate >> Institute of Electronic Structure and Laser (I.E.S.L.) >> Foundation for Research and Technology Hellas (FO.R.T.H.) >> Vassilika Vouton P.O. Box 1527 71003 Heraklion Crete Greece >> Phone +30 2810 391824 >> FAX +30 2810 391305 >> webpage: http://esperia.iesl.forth.gr/~fthenak >> ********************************************************** >> >> >
