Dear Prof. Marks, Just a quick question: if someone reduce the greed to a very low value but go back to the default values in case.inm for the last iterations, is it safe ? All the best, Luis
2014-04-24 9:15 GMT-03:00 Laurence Marks <l-ma...@northwestern.edu>: > Why did you change case.inm away from the defaults? > > a) Set the greed to 0.2 not 0.005. As I have said before, this does > not do what you think it does and concepts such as "reduce the mixing > factor if it does not converge" are wrong. Yes, wrong. Very wrong. > Completely wrong. Always wrong. To understand more please read Journal > of Chemical Theory and Computation 9 (2013) 2786. > > b) Use MSR1, and in extreme cases perhaps MSEC3. Do not use BROYD. > Perhaps reduce the greed to 0.1, almost never less than this. > > A little explanation. The factor of "0.005" is called the mixing > greed.in the spirit of algorithm greed (e.g. > http://en.wikipedia.org/wiki/Greedy_algorithm). If it is too large the > self-consistent iterations can become unstable. However, you rarely > need to deal with this and the mixer does. If you set it too a small > value (which you did) you are making the algorithm take such tiny > steps that it can starve to death. The code "honors" the user setting > of a very small value (at least in 12.1) under the assumption that the > user knows what he/she is doing. > > On Thu, Apr 24, 2014 at 5:25 AM, Martin Gmitra <martin.gmi...@gmail.com> > wrote: > > Dear Wien2k users, > > > > I am doing calculations of a hexaboride films invoking: runsp_c_lapw -so > > -eece > > My problem is two fold: > > > > (i) SCF calculations successfully converged for thin films (9 atomic > units) > > and bulk systems. I do have a problem to converge a thicker film (11 > atomic > > units) even TEMP broadening of 0.02 is used. The observations after 800 > > iterations are following: > > > > (1) fermi energy is jumping (roughly) between two values > > :FER : F E R M I - ENERGY(FERMI-SM.)= 0.3682855520 > > :FER : F E R M I - ENERGY(FERMI-SM.)= 0.3682855520 > > :FER : F E R M I - ENERGY(FERMI-SM.)= -0.7779431003 > > :FER : F E R M I - ENERGY(FERMI-SM.)= -0.7779431003 > > :FER : F E R M I - ENERGY(FERMI-SM.)= 0.3683943150 > > :FER : F E R M I - ENERGY(FERMI-SM.)= 0.3683943150 > > :FER : F E R M I - ENERGY(FERMI-SM.)= -0.7767634505 > > :FER : F E R M I - ENERGY(FERMI-SM.)= -0.7767634505 > > > > (2) charge distance non uniformly oscillates between 0.1 and 0.001 > > :DIS : CHARGE DISTANCE ( 1.1067771 for atom 4 spin 1) > > 0.1064425 > > :DIS : CHARGE DISTANCE ( 0.0059078 for atom 6 spin 1) > > 0.0013328 > > :DIS : CHARGE DISTANCE ( 0.0092322 for atom 6 spin 1) > > 0.0015769 > > :DIS : CHARGE DISTANCE ( 0.0092664 for atom 6 spin 1) > > 0.0015106 > > :DIS : CHARGE DISTANCE ( 0.5478509 for atom 4 spin 1) > > 0.0466613 > > :DIS : CHARGE DISTANCE ( 0.0078766 for atom 6 spin 1) > > 0.0014700 > > :DIS : CHARGE DISTANCE ( 0.9814094 for atom 4 spin 1) > > 0.0939173 > > :DIS : CHARGE DISTANCE ( 0.0070829 for atom 6 spin 1) > > 0.0015672 > > :DIS : CHARGE DISTANCE ( 0.0411319 for atom 4 spin 2) > > 0.0053433 > > :DIS : CHARGE DISTANCE ( 0.0072009 for atom 6 spin 1) > > 0.0014308 > > :DIS : CHARGE DISTANCE ( 0.1357701 for atom 4 spin 2) > > 0.0150618 > > > > (3) magnetic moments are zero within spheres whereas there is > > :MMTOT: SPIN MAGNETIC MOMENT IN CELL = -0.00010 > > :MMINT: MAGNETIC MOMENT IN INTERSTITIAL = -0.00003 > > > > (4) my case.inm > > BROYD 0.0 YES (BROYD/PRATT, extra charge (+1 for additional e), norm) > > 0.005 mixing FACTOR for BROYD/PRATT scheme > > 1.00 1.00 PW and CLM-scaling factors > > 9999 8 idum, HISTORY > > > > :MIX : MSEC3 REGULARIZATION: 2.50E-04 GREED: 0.005 Newton 1.000 > > with PRATT after 100 iterations > > MIX : PRATT REGULARIZATION: 2.50E-04 GREED: 0.005 > > > > Do you have any hints how to converge the calculations? > > > > (ii) I am running the calculations with version 12.1. The runsp_c_lapw > > script has been updated (debugged) in version 13.1 but SCF diverges in my > > cases (thin and thicker films). > > > > Does anybody experience similar problem? > > > > Best regards, > > Martin Gmitra > > Uni Regensburg > > > > > > > > > > -- > Professor Laurence Marks > Department of Materials Science and Engineering > Northwestern University > www.numis.northwestern.edu 1-847-491-3996 > "Research is to see what everybody else has seen, and to think what > nobody else has thought" > Albert Szent-Gyorgi > _______________________________________________ > 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 >
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