Dear Prof. Marks, Thanks for your elaborations. These will be helpful.
with regards, On Mon, 9 Aug 2021 at 19:25, Laurence Marks <laurence.ma...@gmail.com> wrote: > This type of question has come up many times, so let me expand/clarify > what Peter said. > > In general, you can optimize positions and converge the density using a > smaller number of k-points and also a smaller RKMAX. You then save this > density and improve both the k-points and RKMAX, and sometimes also the > RMTs (using reduce_rmt_lapw with the "-a" option). In most cases the forces > only change by a few mRyd/au. While the energy and how much of the density > is within the RMTs will change, normally it will converge in these > "improved" runs in a small (5-10) number of iterations. This is much less > than the 20-50 that are normally required to converge from atomic densities > [1]. > > The reason that Peter recommended saving the prior run is just in case > something goes wrong. (Even experienced useres sometimes mess up!) > > [1] If you need more than 50 iterations to converge just the densities > (fixed positions), you may have something wrong with your model. > > On Mon, Aug 9, 2021 at 8:22 AM Peter Blaha <pbl...@theochem.tuwien.ac.at> > wrote: > >> What do you mean by "can I wait for scf convergence with 4 k-points in a >> new folder ???? >> >> Even in a new folder: NEVER do an init_lapw >> again, but always use the previous saved files. >> >> mkdir new >> cd new >> cp ../relaxed_4k-points.* . >> restore relaxed_4k-points >> >> x kgen with better k-mesh >> >> runsp_lapw ... >> >> >> -------- Weitergeleitete Nachricht -------- >> Betreff: Query about denser k-mesh for calculating more accurate >> total >> energy/unit cell >> Datum: Mon, 9 Aug 2021 17:58:13 +0530 >> Von: shamik chakrabarti <shamik15041...@gmail.com> >> An: pbl...@theochem.tuwien.ac.at >> >> >> >> Dear Prof. Blaha, >> As has been discussed in the wien2k >> mailing list I am following your advice regarding the structure >> optimization & steps to be followed after runsp_lapw -fc 1.0 -ec 0.0001 >> -cc 0.0001 -min. >> >> save_lapw relaxed_4k-points (if not already done) >> x kgen with as many k-points as you want. >> runsp ... (first without -min, because most likely the forces will not >> change with the bigger k-mesh). -- >> >> Here I have a query. Can I wait till the convergence is achieved with 4 >> k points (during total energy calculation in a new folder)& then (after >> convergence with 4 k points) increase the k-points to 14 k points? >> >> with regards, >> >> Dr. Shamik Chakrabarti >> Research Fellow >> Department of Physics >> Indian Institute of Technology Patna >> Bihta-801103 >> Patna >> Bihar, India >> _______________________________________________ >> Wien mailing list >> Wien@zeus.theochem.tuwien.ac.at >> >> https://urldefense.com/v3/__http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien__;!!Dq0X2DkFhyF93HkjWTBQKhk!A0fR70GC0UYtbhJl4TwLdfZeFN8NsDYDt3pQIReHtL5-hz2vOOUTdWINozbuynIocXtQsQ$ >> SEARCH the MAILING-LIST at: >> https://urldefense.com/v3/__http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html__;!!Dq0X2DkFhyF93HkjWTBQKhk!A0fR70GC0UYtbhJl4TwLdfZeFN8NsDYDt3pQIReHtL5-hz2vOOUTdWINozbuynIYZHVwHQ$ >> > > > -- > Professor Laurence Marks > Department of Materials Science and Engineering > Northwestern University > www.numis.northwestern.edu > "Research is to see what everybody else has seen, and to think what nobody > else has thought" Albert Szent-Györgyi > _______________________________________________ > Wien mailing list > Wien@zeus.theochem.tuwien.ac.at > http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien > SEARCH the MAILING-LIST at: > http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html > -- Dr. Shamik Chakrabarti Research Fellow Department of Physics Indian Institute of Technology Patna Bihta-801103 Patna Bihar, India
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