Dear friends, Have you ever computed the average Coulomb repulse U and exchange parameter J by pwscf. Could someone give some more detailed explanation about how to process the output to get the U and J. I have read this pape(PHYSICAL REVIEW B 71, 035105, 2005), but I am still confusing about how to get U. Thank you in advance. All the best, Zhi Li
----------------------------------------------- Ex5 group Extreme Condition Physics, Institute of Physics, Chinese Academy of Sciences, P. O. Box 603, Beijing, 100190, People?s Republic of China pw_forum-request at pwscf.org ?: > Send Pw_forum mailing list submissions to > pw_forum at pwscf.org > > To subscribe or unsubscribe via the World Wide Web, visit > http://www.democritos.it/mailman/listinfo/pw_forum > or, via email, send a message with subject or body 'help' to > pw_forum-request at pwscf.org > > You can reach the person managing the list at > pw_forum-owner at pwscf.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Pw_forum digest..." > > > Today's Topics: > > 1. Re: Convergence Problem (??) > 2. Re: Convergence Problem (??) > 3. Re: Convergence Problem (Prasenjit Ghosh) > 4. Re: Convergence Problem (Gabriele Sclauzero) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 16 Apr 2009 11:31:53 +0800 > From: ?? <panda.deng.pan at gmail.com> > Subject: Re: [Pw_forum] Convergence Problem > To: PWSCF Forum <pw_forum at pwscf.org> > Message-ID: <c8dadee0904152031x8bb7e7i291265ff754d2b24 at mail.gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > maybe the ecutwfc value is small. > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090416/ db25a9e5/attachment.html > > ------------------------------ > > Message: 2 > Date: Wed, 15 Apr 2009 22:42:42 -0500 > From: ?? <sunyang198498 at gmail.com> > Subject: Re: [Pw_forum] Convergence Problem > To: PWSCF Forum <pw_forum at pwscf.org> > Message-ID: > <98e7a0810904152042y7cb45757v5ee316165c8a8315 at mail.gmail.com> > Content-Type: text/plain; charset=GB2312 > > Thanks for your advice, Deng. > > Yang > > 2009/4/15 ?? <panda.deng.pan at gmail.com>: >> maybe the ecutwfc value is small. >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> >> > > > > -- > University of Nebraska at Lincoln > > > ------------------------------ > > Message: 3 > Date: Thu, 16 Apr 2009 07:57:38 +0200 > From: Prasenjit Ghosh <prasenjit.jnc at gmail.com> > Subject: Re: [Pw_forum] Convergence Problem > To: PWSCF Forum <pw_forum at pwscf.org> > Message-ID: > <627e0ffa0904152257r2552670cg902685e718d73022 at mail.gmail.com> > Content-Type: text/plain; charset="gb2312" > > Hi Yang, > > Here are a few general suggestions: > > (1) Check the convergence wrt to vacuum (distance between periodic images). > In ur case it seems too small to me, as a result of which the periodic > images are interacting. I think this is specially important for ur case > because ur having an external electric field. > > (2) check convergence wrt ecutrho & ecutwfc. Ususally ecutrho is 10-12 times > ecutwfc. (probably ur wave fn is not converged) > > (3) a value of mixing beta=0.05 is too low. Such a low value often implies > that you don't move the electrons at all......hence its not very > effective........according to my experience, at least for cal. without > electric field, a value of 0.2-0.3 works well. > > (4) Also you are doing a slab cal. and usually either a few layers at the > bottom or a few in the middle are kept fixed (although this should not > affect ur electronic minimization). > > With regards, > Prasenjit. > > > > (5) ur value of conv_thr seem too high.....at least u should use the default > value. But I would suggest u to use something of the order of 10^-8. > > 2009/4/16 ?? <sunyang198498 at gmail.com> > >> Thanks for your advice, Deng. >> >> Yang >> >> 2009/4/15 ?? <panda.deng.pan at gmail.com>: >> > maybe the ecutwfc value is small. >> > >> > _______________________________________________ >> > Pw_forum mailing list >> > Pw_forum at pwscf.org >> > http://www.democritos.it/mailman/listinfo/pw_forum >> > >> > >> >> >> >> -- >> University of Nebraska at Lincoln >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum at pwscf.org >> http://www.democritos.it/mailman/listinfo/pw_forum >> > > > > -- > PRASENJIT GHOSH, > POST-DOC, > ROOM NO: 265, MAIN BUILDING, > CM SECTION, ICTP, > STRADA COSTERIA 11, > TRIESTE, 34104, > ITALY > PHONE: +39 040 2240 369 (O) > +39 3807528672 (M) > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: http://www.democritos.it/pipermail/pw_forum/attachments/20090416/ e3043d76/attachment-0001.htm > > ------------------------------ > > Message: 4 > Date: Thu, 16 Apr 2009 08:43:06 +0200 > From: Gabriele Sclauzero <sclauzer at sissa.it> > Subject: Re: [Pw_forum] Convergence Problem > To: PWSCF Forum <pw_forum at pwscf.org> > Message-ID: <49E6D37A.1090506 at sissa.it> > Content-Type: text/plain; charset=us-ascii; format=flowed > > On top of what alreay said by the other users, I would suggest few more things: >> Below is the input file. Any suggestion is highly appreciated. >> >> >> >> >> &control >> calculation='scf' >> restart_mode='from_scratch', >> pseudo_dir = '$PSEUDO_DIR/', >> outdir='$TMP_DIR/' >> prefix='Pd' >> tefield = .true. >> dipfield = .true. >> nstep = 300 >> >> / >> &system >> ibrav = 6 >> celldm(1) = 7.3331 >> nspin = 2 >> celldm(3) = 4.5 >> edir = 3 >> emaxpos=0.72 >> eopreg=0.28 >> eamp = -0.001944 > > I don't know much about efield calculations, but I suppose that you are sure that you > placed the discontinuity of the potential in the vacuum, as should be done. > >> starting_magnetization=0.05 > > To be rigorous, starting_magnetization is a vector. In order to avoid strange surprises, > you should specify > starting_magnetization(1)=0.05 > ... > >> ntyp = 1 >> nat= 14 >> ecutwfc = 25.0, >> ecutrho = 500.0, >> occupations='smearing', >> degauss=0.2 > > This value of degauss (which is in Ryd, NOT eV) seems exceedingly high to me. I would use > something like at least 1 order of magnitude smaller (but you should test convergence by > yourself, together with the k-point mesh). > > You may also want to try different kind of smearing methods. Methfessel- Paxton usually > works well with metals (smearing="mp") > >> nbnd=160 > > Usually there is no need to specify the number of bands when using smearing. The number of > bands which will be computed is automatically increased by the program to a safe choice. > >> / >> >> &electrons >> conv_thr = 1.0e-4 > > See Ghosh's reply... > >> mixing_mode='local-TF' > > have you tried a different mixing mode? I don't know if this is well suited for slab > calculations. > > > HTH > > GS > >> mixing_beta = 0.05 >> mixing_ndim = 12 >> >> / >> ATOMIC_SPECIES >> Pd 100 Pd.pz-nd-rrkjus.UPF >> ATOMIC_POSITIONS >> Pd 0.500000000 0.000000000 -1.496126804 >> Pd 0.000000000 0.500000000 -1.496126804 >> Pd 0.000000000 0.000000000 -1.002542052 >> Pd 0.500000000 0.500000000 -1.002542051 >> Pd 0.500000000 0.000000000 -0.501470158 >> Pd 0.000000000 0.500000000 -0.501470158 >> Pd 0.000000000 0.000000000 0.000000000 >> Pd 0.500000000 0.500000000 0.000000000 >> Pd 0.500000000 0.000000000 0.501470158 >> Pd 0.000000000 0.500000000 0.501470158 >> Pd 0.000000000 0.000000000 1.002542052 >> Pd 0.500000000 0.500000000 1.002542051 >> Pd 0.500000000 0.000000000 1.496126804 >> Pd 0.000000000 0.500000000 1.496126804 >> >> >> >> >> K_POINTS (automatic) >> 8 8 1 0 0 0 >> >> >> > > -- > > > o ------------------------------------------------ o > | Gabriele Sclauzero, PhD Student | > | c/o: SISSA & CNR-INFM Democritos, | > | via Beirut 2-4, 34014 Trieste (Italy) | > | email: sclauzer at sissa.it | > | phone: +39 040 3787 511 | > | skype: gurlonotturno | > o ------------------------------------------------ o > > > ------------------------------ > > _______________________________________________ > Pw_forum mailing list > Pw_forum at pwscf.org > http://www.democritos.it/mailman/listinfo/pw_forum > > > End of Pw_forum Digest, Vol 22, Issue 34 > ****************************************
