[Pw_forum] convergence problem in scf calculation in rare earth oxide Sm2O3

[Thomas Brumme]

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 list
> Pw_forum at pwscf.org
> 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: thomas.brumme at uni-leipzig.de

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20171129/e46b2738/attachment.html>