[Pw_forum] scf_must_converge

[Bramha Pandey]

On Fri, Nov 2, 2012 at 3:09 PM, florence liu <florenceliu86 at gmail.com>wrote:

> Dear Davide, Dear Bramha,
>
> thankyou for your answers.
> i am only optimizing atomic positions of a Pt surface with vdw-DF
> funtionals,.... so nothing too special, i guess.
>
> as you suggested, here is the complete input file:
>
>
>  &control
>     prefix='Ptsurface47',
>     pseudo_dir= '(...)',
>     outdir = '(...)',
>     calculation='scf',
>
As per your problem you want to optimize, so set 'relax' or 'vc-relax' in
calculation field.

>     forc_conv_thr=0.000389,
>     tefield=.TRUE.,
>     dipfield=.TRUE.,
>  /
>  &system
>     ibrav=  0,  nat=  16, ntyp= 1,
>     ecutwfc = 47, occupations='smearing', smearing='gaussian',
>     degauss= 0.00367487
>
it seems very low value to me. set it as a 0.02 or 0.01. and apply what i
am already said before.

>     edir=3,
>     emaxpos=0.6,
>     eopreg=0.1,
>     input_dft='sla+pw+rpb+vdw1'
>  /
>  &electrons
>  electron_maxstep=100,
>  conv_thr=7.35D-8,
>  scf_must_converge=.false.
>  /
>  &ions
>  /
>  &cell
>  /
> CELL_PARAMETERS (angstrom)
> 5.7210401300000000    0.0000000000000000    0.0000000000000000
> 2.8605200700000000    4.9545660900000000    0.0000000000000000
> 0.0000000000000000    0.0000000000000000   22.9590000000000000
> ATOMIC_SPECIES
>  Pt  196.966   Pt.revPBE-n-kjpaw.UPF
> ATOMIC_POSITIONS (crystal)
> Pt  0.0000000000000000  0.0000000000000000  0.3051881400000000 1 1 1
> Pt  0.5000000000000000  0.0000000000000000  0.3051881400000000 1 1 1
> Pt  0.0000000000000000  0.5000000000000000  0.3051881400000000 1 1 1
> Pt  0.5000000000000000  0.5000000000000000  0.3051881400000000 1 1 1
> Pt  0.3333333333333333  0.3333333333333333  0.2034587900000000 1 1 1
> Pt  0.8333333333333333  0.3333333333333333  0.2034587900000000 1 1 1
> Pt  0.3333333333333333  0.8333333333333333  0.2034587900000000 1 1 1
> Pt  0.8333333333333333  0.8333333333333333  0.2034587900000000 1 1 1
> Pt  0.1666666666666666  0.1666666666666666  0.1017293800000000 0 0 0
> Pt  0.6666666666666666  0.1666666666666666  0.1017293800000000 0 0 0
> Pt  0.1666666666666666  0.6666666666666666  0.1017293800000000 0 0 0
> Pt  0.6666666666666666  0.6666666666666666  0.1017293800000000 0 0 0
> Pt  0.0000000000000000  0.0000000000000000  0.0000000000000000 0 0 0
> Pt  0.5000000000000000  0.0000000000000000  0.0000000000000000 0 0 0
> Pt  0.0000000000000000  0.5000000000000000  0.0000000000000000 0 0 0
> Pt  0.5000000000000000  0.5000000000000000  0.0000000000000000 0 0 0
>
> K_POINTS (automatic)
> 5 5 1 0 0 0
>
>
>
>
> 2012/11/2 Davide Ceresoli <davide.ceresoli at istm.cnr.it>
>
>> Dear Florence,
>>      which kind of relaxation are you performing? ions, cell, ions+cell?
>> are you using hybrid functionals? the logic of PW/src/electrons.f90 is
>> quite complicated and there are several points in which one can check
>> if (last_step .and. .not. scf_must_converge). If you send me a fragment
>> of the output, I can have a look.
>>
>> Best wishes,
>> Davide
>>
>>
>> On 11/02/2012 08:06 AM, florence liu wrote:
>> > Dear all,
>> > i am trying to do some optimizations with PWSCF v.5.0 and I have the
>> following
>> > problem.
>> > I want to let a optimization to continue, even if the scf has not fully
>> > converged. As I have under stood the QE documentation, one need to set
>> the tag
>> > scf_must converge, as i have done in my input file:
>> > (...)
>> >   &electrons
>> >   electron_maxstep=100,
>> >   conv_thr=7.35D-8,
>> >   scf_must_converge=.false.
>> > /
>> > (...)
>> > however, the optimization calcualtion still terminated with the message:
>> > "convergence NOT achieved after 100 iterations: stopping" after one scf
>> cycle,
>> > in whihch the convergence critereriva have not been reached.
>> > Can anybody tell me, whether I am missing some settings to let the
>> optimization
>> > not terminate, when a scf cycle has not converged? or does anybody see
>> which
>> > mistake i have done?
>> > best wishes,
>> > florence
>> > TU Munich
>> >
>>
>> --
>> +--------------------------------------------------------------+
>>    Davide Ceresoli
>>    CNR Institute of Molecular Science and Technology (CNR-ISTM)
>>    c/o University of Milan, via Golgi 19, 20133 Milan, Italy
>>    Email: davide.ceresoli at istm.cnr.it
>>    Phone: +39-02-50314276, +39-347-1001570 (mobile)
>>    Skype: dceresoli
>> +--------------------------------------------------------------+
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>
>
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-- 
Thanks and Regards
Bramha Prasad Pandey
Indian School of Mines(ISM)
Dhanbad, INDIA.
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