[Pw_forum] Problem in SCF convergence with larger unit cells
reza vatan
rezavatan64 at gmail.com
Sun Jun 12 00:00:50 CEST 2016
Dear Giuseppe,
I had tried the calculations with higher ecutwfc before and as you said it
perfectly worked. But the problem is that the calculations take much
longer. Is there any way to keep the ecutwfc as small as possible and use
different pseudopotentials and still get convergence? Please advise.
Many thanks in advance.
Regards,
Reza
On Sat, Jun 11, 2016 at 2:21 PM, Giuseppe Mattioli <
giuseppe.mattioli at ism.cnr.it> wrote:
>
> Dear Reza Vatan
>
> > ecutwfc = 12.0,
>
> > Ga 69.72 Ga.blyp-d-hgh.UPF
> > P 30.97 P.blyp-hgh.UPF
>
> It is very strange that you converge at all with a so minimal cutoff
> and so hard hgh norm-conserving pseudopotentials. I would bet that
> ecutwfc = 100.0 is barely sufficient for Ga with semicore d shell in
> valence. I suggest that you raise ecutwfc and find convergence for GaP
> in the 2 atoms cell.
> HTH
> Giuseppe
>
> Quoting reza vatan <rezavatan64 at gmail.com>:
>
> > Dear all,
> >
> > I'm trying to optimize the atomic structure of GaP using QE. When I use a
> > unit cell only containing two atoms, I have no problem in SCF convergence
> > and the structure get optimized in the first step. But when I make my
> unit
> > cell bigger (let's say a unit cell with 64 atoms) just by repeating my
> > smaller optimized unit cell in real space and run relax calculation, the
> > SCF calculation never get converged. Does anyone know where the problem
> is?
> >
> > Following is my input:
> >
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> > &CONTROL
> > calculation = "relax",
> > dt = 30.D0,
> > prefix = 'gap',
> > pseudo_dir = './',
> > outdir='./',
> > /
> > &system
> > ibrav= 6, celldm(1) =20.52, celldm(3) =1, nat= 64, ntyp= 2,
> > ecutwfc = 12.0,
> > degauss = 0.05D0,
> > occupations = "fixed",
> > smearing = "methfessel-paxton",
> > /
> > &ELECTRONS
> > conv_thr = 1.D-7,
> > mixing_beta = 0.3D0,
> > electron_maxstep= 200,
> > /
> > &IONS
> > pot_extrapolation = "second_order",
> > wfc_extrapolation = "second_order",
> > /
> > ATOMIC_SPECIES
> > Ga 69.72 Ga.blyp-d-hgh.UPF
> > P 30.97 P.blyp-hgh.UPF
> > ATOMIC_POSITIONS (angstrom)
> > Ga 2.7146780000 2.7146780000 0.0000000000
> > Ga 0.0000000000 0.0000000000 0.0000000000
> > Ga 2.7146780000 0.0000000000 2.7146780000
> > Ga 0.0000000000 2.7146780000 2.7146780000
> > P 4.0720170000 4.0720170000 1.3573390000
> > P 1.3573390000 1.3573390000 1.3573390000
> > P 4.0720170000 1.3573390000 4.0720170000
> > P 1.3573390000 4.0720170000 4.0720170000
> > Ga 2.7146780000 2.7146780000 5.4293560000
> > Ga 0.0000000000 0.0000000000 5.4293560000
> > Ga 2.7146780000 0.0000000000 8.1440340000
> > Ga 0.0000000000 2.7146780000 8.1440340000
> > P 4.0720170000 4.0720170000 6.7866950000
> > P 1.3573390000 1.3573390000 6.7866950000
> > P 4.0720170000 1.3573390000 9.5013730000
> > P 1.3573390000 4.0720170000 9.5013730000
> > Ga 2.7146780000 8.1440340000 0.0000000000
> > Ga 0.0000000000 5.4293560000 0.0000000000
> > Ga 2.7146780000 5.4293560000 2.7146780000
> > Ga 0.0000000000 8.1440340000 2.7146780000
> > P 4.0720170000 9.5013730000 1.3573390000
> > P 1.3573390000 6.7866950000 1.3573390000
> > P 4.0720170000 6.7866950000 4.0720170000
> > P 1.3573390000 9.5013730000 4.0720170000
> > Ga 2.7146780000 8.1440340000 5.4293560000
> > Ga 0.0000000000 5.4293560000 5.4293560000
> > Ga 2.7146780000 5.4293560000 8.1440340000
> > Ga 0.0000000000 8.1440340000 8.1440340000
> > P 4.0720170000 9.5013730000 6.7866950000
> > P 1.3573390000 6.7866950000 6.7866950000
> > P 4.0720170000 6.7866950000 9.5013730000
> > P 1.3573390000 9.5013730000 9.5013730000
> > Ga 8.1440340000 2.7146780000 0.0000000000
> > Ga 5.4293560000 0.0000000000 0.0000000000
> > Ga 8.1440340000 0.0000000000 2.7146780000
> > Ga 5.4293560000 2.7146780000 2.7146780000
> > P 9.5013730000 4.0720170000 1.3573390000
> > P 6.7866950000 1.3573390000 1.3573390000
> > P 9.5013730000 1.3573390000 4.0720170000
> > P 6.7866950000 4.0720170000 4.0720170000
> > Ga 8.1440340000 2.7146780000 5.4293560000
> > Ga 5.4293560000 0.0000000000 5.4293560000
> > Ga 8.1440340000 0.0000000000 8.1440340000
> > Ga 5.4293560000 2.7146780000 8.1440340000
> > P 9.5013730000 4.0720170000 6.7866950000
> > P 6.7866950000 1.3573390000 6.7866950000
> > P 9.5013730000 1.3573390000 9.5013730000
> > P 6.7866950000 4.0720170000 9.5013730000
> > Ga 8.1440340000 8.1440340000 0.0000000000
> > Ga 5.4293560000 5.4293560000 0.0000000000
> > Ga 8.1440340000 5.4293560000 2.7146780000
> > Ga 5.4293560000 8.1440340000 2.7146780000
> > P 9.5013730000 9.5013730000 1.3573390000
> > P 6.7866950000 6.7866950000 1.3573390000
> > P 9.5013730000 6.7866950000 4.0720170000
> > P 6.7866950000 9.5013730000 4.0720170000
> > Ga 8.1440340000 8.1440340000 5.4293560000
> > Ga 5.4293560000 5.4293560000 5.4293560000
> > Ga 8.1440340000 5.4293560000 8.1440340000
> > Ga 5.4293560000 8.1440340000 8.1440340000
> > P 9.5013730000 9.5013730000 6.7866950000
> > P 6.7866950000 6.7866950000 6.7866950000
> > P 9.5013730000 6.7866950000 9.5013730000
> > P 6.7866950000 9.5013730000 9.5013730000
> > K_POINTS {automatic}
> > 2 2 2 0 0 0
> > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >
> >
> > Thanks in advance.
> >
> > Regards,
> > Reza Vatan
> > School of Electrical, Computer and Energy Engineering
> > Arizona State University
>
>
> --
> ********************************************************
> - Article premier - Les hommes naissent et demeurent
> libres et égaux en droits. Les distinctions sociales
> ne peuvent être fondées que sur l'utilité commune
> - Article 2 - Le but de toute association politique
> est la conservation des droits naturels et
> imprescriptibles de l'homme. Ces droits sont la liberté,
> la propriété, la sûreté et la résistance à l'oppression.
> ********************************************************
>
> Giuseppe Mattioli
> CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
> v. Salaria Km 29,300 - C.P. 10
> I 00015 - Monterotondo Stazione (RM)
> Tel + 39 06 90672836 - Fax +39 06 90672316
> E-mail: <giuseppe.mattioli at ism.cnr.it>
> http://www.ism.cnr.it/en/staff/giuseppe-mattioli/
> ResearcherID: F-6308-2012
>
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20160611/df40181f/attachment.html>
More information about the users
mailing list