[Pw_forum] convergence is not achieved, please help!!!

zahra vatankhah vatankhah.z at gmail.com
Sat Nov 30 20:57:34 CET 2013


Dear Ganjar
I think it'll help you if you choose a lower value for mixing_beta and try
the calculations again.

with regards


On Fri, Nov 29, 2013 at 10:07 PM, Giuseppe Mattioli <
giuseppe.mattioli at ism.cnr.it> wrote:

>
> Dear Ganjar
>
> > About the parameter of pseudopotential, Prevously I have calculate
> > LiFeSiO4 with the same parameters that I use here and the
> > calculation is succesfull. But I dont know why for this case is not.
>
> This is very strange... You are using norm conserving pseudopotentials
> (mt indicates a Martins-Troullier norm conserving pseudopotential)
> which should be quite hard. They should require (at least) ecutwfc >=
> 100, but you should check the convergence wrt ecutwfc, and I would not
> be surprised by a final ecutwfc=140~150.
>
> HTH
>
> Giuseppe
>
> Giuseppe Mattioli
> ISM-CNR
> Italy
>
> Quoting Ganjar Kurniawan <zargan88 at yahoo.com>:
>
> > Thanks for the suggestions.....
> > I have checked the structure using Xcrysden and then compared with
> > the literature. I find that there is no problem with the structure,
> > so I`m sure that the it is right.
> > About the parameter of pseudopotential, Prevously I have calculate
> > LiFeSiO4 with the same parameters that I use here and the
> > calculation is succesfull. But I dont know why for this case is not.
> >
> >
> >
> >
> > On Friday, 29 November 2013 4:46 PM, Vikan Manmathan
> > <vikanmanmathan1 at gmail.com> wrote:
> >
> > Dear Ganjar Kurniawan,
> > Read the input structure first.
> >
> http://www.quantum-espresso.org/wp-content/uploads/Doc/INPUT_PW.html#id3119661
> > Try to visualize the structure before running the calculations,
> > using some graphical software like Xcrysden.
> >
> >
> >
> >
> > On Fri, Nov 29, 2013 at 1:37 PM, Axel Kohlmeyer <akohlmey at gmail.com>
> wrote:
> >
> > On Fri, Nov 29, 2013 at 8:20 AM, Ganjar Kurniawan <zargan88 at yahoo.com>
> wrote:
> >>> Dear QE user...
> >>> I`m trying to optimize geometry of Li2FeSiO4 structure using 'relax',
> but
> >>> the result said that the " convergence NOT achieved after 100
> iterations:
> >>> stopping ". I have used the atomic position from the literature.
> >>> here it is the input that i use
> >>
> >> hmm... you seem to be using norm-conserving pseudopotentials, but use
> >> wavefunction/density cutoff values that are commonly used for
> >> ultra-soft pseudo-potentials. is there are specific reason for this?
> >>
> >> axel.
> >>
> >>
> >>
> >>> &CONTROL
> >>>  calculation = 'relax',
> >>>  restart_mode = 'from_scratch',
> >>>  nstep = 50
> >>>  outdir = '/home/ganjar/Li2FeSiO4/pmn21/normal/relax'
> >>>  pseudo_dir = '/share/apps/espresso-5.0.2/pseudo',
> >>>  prefix='files_lar'
> >>>  tprnfor = .true.
> >>>  tstress = .true.
> >>>  etot_conv_thr = 1.0D-4, forc_conv_thr = 1.0D-2
> >>> /
> >>> &SYSTEM
> >>> ibrav=0, a = 6.3219, b = 5.3935, c = 4.9939, cosAB = 0, cosAC = 0,
> cosBC =
> >>> 0, nat = 16, ntyp = 4, ecutwfc = 30, ecutrho = 240,
> >>>  occupations = 'smearing', smearing='marzari-vanderbilt', degauss=
> 0.015,
> >>> nspin=1
> >>> /
> >>> &ELECTRONS
> >>>
> >>>  conv_thr = 1.0D-8
> >>>  diagonalization = 'david',  mixing_beta = 0.7, startingpot = 'atomic',
> >>> startingwfc = 'random', tqr = .true.
> >>> /
> >>> &IONS
> >>>  ion_dynamics = 'bfgs'
> >>> /
> >>> ATOMIC_SPECIES
> >>>  Li  6.9410  Li.pbe-mt_fhi.UPF
> >>>  Fe  55.847  Fe.pbe-mt_fhi.UPF
> >>>  Si  28.085  Si.pbe-mt_fhi.UPF
> >>>  O   15.999  O.pbe-mt_fhi.UPF
> >>> CELL_PARAMETERS alat
> >>>
> >>>  1.000   0.000   0.000
> >>>  0.000   1.000   0.000
> >>>  0.000   0.000   1.000
> >>>
> >>> ATOMIC_POSITIONS alat
> >>>
> >>> Li  0.2498  0.3307  0.8023
> >>> Li  0.2501  0.6693  0.3023
> >>> Li  0.7498  0.6693  0.3023
> >>> Li  0.7501  0.3307  0.8023
> >>> Fe  0.5000  0.8261  0.7960
> >>> Fe  0.0000  0.1738  0.2960
> >>> Si  0.0000  0.8297  0.8112
> >>> Si  0.5000  0.1702  0.3112
> >>> O   0.2145  0.6849  0.7013
> >>> O   0.2854  0.3150  0.2013
> >>> O   0.7145  0.3150  0.2013
> >>> O   0.7854  0.6849  0.7013
> >>> O   0.0000  0.1231  0.7118
> >>> O   0.5000  0.8768  0.2118
> >>> O   0.5000  0.1794  0.6417
> >>> O   0.0000  0.8205  0.1417
> >>>
> >>> K_POINTS automatic
> >>> 2 4 4 0 0 0
> >>>
> >>> what wrong with my input???
> >>> anybody can correct it??
> >>>
> >>> Best regard
> >>> Ganjar Kurniawan
> >>> Bandung Institute of Technology, Indonesia
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> Pw_forum mailing list
> >>> Pw_forum at pwscf.org
> >>> http://pwscf.org/mailman/listinfo/pw_forum
> >>
> >>
> >>
> >> --
> >> Dr. Axel Kohlmeyer  akohlmey at gmail.com  http://goo.gl/1wk0
> >> International Centre for Theoretical Physics, Trieste. Italy.
> >>
> >> _______________________________________________
> >> Pw_forum mailing list
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> >> http://pwscf.org/mailman/listinfo/pw_forum
> >>
> >
> >
> > --
> >
> > NANDHA KUMAR V.
> > Research scholar,
> >
> > IISER, PUNE.
> >
> >
> > _______________________________________________
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>
> --
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>
>     Giuseppe Mattioli
>     CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
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-- 
Zahra Vatankhah
M.S. student of solid state physics
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