Dear Thomas, Thank you so much. Regards Mohammed
On Thu, Nov 30, 2017 at 3:06 PM Thomas Brumme <[email protected]> wrote: > Dear Mohammed, > > it's hard to give a general advice also because I didn't do many > calculation with rare earth elements. Just checking the headers of the > pseudos from the vlab side it seems both pseudos (LDA and GGA) have the > same states in valence (l_max=3, number_of_wfc=number_of_proj=8). Did you > try what they suggest on their side, i.e.: > > "In some cases, defining orbital occupations (starting_ns_eigenvalue tag > in Quantum ESPRESSO) is essential in order to converge calculations." > > Maybe this can help to achieve convergence!? Otherwise, it might also help > to ask them... Or try using the PAW pseudos from the pslibrary without the > f-states, e.g., Sm.pbe-spdn-kjpaw_psl.1.0.0.UPF (or the ultrasoft one: > Sm.pbe-spdn-rrkjus_psl.1.0.0.UPF). > > And, of course, try what Karim and Ari said: > - increase ecutrho > - maybe ferromagnetic starting guess is wrong and you have to go for > anti-ferromagnetic > > Regards > > Thomas > > On 30.11.2017 11:43, Mohammed Khalafalla wrote: > > Dear Thomas, > Thank you very much for your comments and suggestions. > You are right the PBE pseudos from > http://www.vlab.msi.umn.edu/resources/repaw/index.shtml contains > f-states, but not the LDA ones (I noticed this simply by looking for > f-states within the pseudo files). So let me double check, shall I use the > LDA ones instead? > Thanks ones more. > Regards, > Mohammed > > > > On 29 November 2017 at 11:24, Thomas Brumme <[email protected]> > wrote: > >> Dear Mohammed, >> >> adding to the comments of Karim and Ari, I think that you should consider >> using a pseudo without f-states - of course depending on what you want to >> predict/calculate. In the end, you use DFT+U to correct for the errors of >> DFT but putting the f-states into the core is a first approximation to this >> idea. And the standard ecutrho of 4 times ecutwfc is definitely not enough >> for PAW potentials if the f shell is included. >> >> Regards >> >> Thomas >> >> On 25.11.2017 20:16, Mohammed Khalafalla wrote: >> >> Dear all, >> I could not achieve scf convergence in Sm2La2O6 (the input file is >> attached herewith). This was the case even after several 'restart' of the >> calculation with different pseudpotentials specially for 'O' atom. I guess >> I used well tested PAW psedu for rare earth from >> http://www.vlab.msi.umn.edu/resources/repaw/index.shtml >> I used recommended hubbard potentials and spin polarization, but no >> change. Generally I found convergence in (Sm,O) system to be difficult. Can >> you kindly let me know which parameter set-up would determine successful >> convergence in (Sm,O) system? >> Regards, >> Mohammed A. H. Khalafalla (PhD) >> Taibah University >> KSA >> >> >> >> _______________________________________________ >> Pw_forum mailing >> [email protected]http://pwscf.org/mailman/listinfo/pw_forum >> >> >> -- >> Dr. rer. nat. Thomas Brumme >> Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry >> Leipzig University >> Phillipp-Rosenthal-Strasse 31 >> 04103 Leipzig >> >> Tel: +49 (0)341 97 36456 >> >> email: [email protected] >> >> > > -- > Dr. rer. nat. Thomas Brumme > Wilhelm-Ostwald-Institute for Physical and Theoretical Chemistry > Leipzig University > Phillipp-Rosenthal-Strasse 31 > 04103 Leipzig > > Tel: +49 (0)341 97 36456 > > email: [email protected] > > -- Sent from Gmail Mobile
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