[Pw_forum] Relax calculation

[Filipe Camargo Dalmatti Alves Lima]

The relax option does NOT optimize the lattice constants.  (useful when you
want to relax impurities of molecules)

The vc-relax option optimize the lattice constants. (useful only you have
crystalline system)

Now it depends what you want to do:

Do you have just a crystal? I should say vc-relax is enough.

Do you have a slab with a molecule attached into the surface? I would first
vc-relax the surface alone; I would insert the molecule, then I would
optimize the geometry using relax option.

If I had just a single molecule, I would create a very large box and just
relax the structure.

In order to be sure that your simulation is ok you must always check the
convergence parameters: total energy, k-point mesh, DOS, forces, etc... all
the time.
Also, keep in mind the convergence depends on the property you want to
investigate.

Is there anything in particular that you have an issue?

Regards,

Filipe





On Fri, Apr 25, 2014 at 6:14 PM, Sohail Ahmad wrote:

> I am using QE 5.0.2 and I have a very basic question.
> To optimise the structure of a material, i started with known experimental
> lattice constants and calculated energy vs lattice to know the optimised
> lattice constants.
>
> Now i wish to apply the strain
> so i increased lattice constant 'a' by 2% (let us say)
>
> now i need to relax (i believe) to get optimised coordinates before
> proceeding further and wish to know force and stress as well.
>
> So my question is i should consider it as 'relax' or "vc relax"
> if relax then following should work but unfortunately no
> tprnfor = .TRUE.
> tstress = .TRUE.
> ion_dynamics = 'bfgs'
> If i donot consider force and stress, then it gives me final coordinates
>
> Is the above step true in this particular set of problems of strain
> application or should i use variable cell.
> i am little confused.
> So
>
> -
>
> *Sohail Ahmad*
> King Khalid University
> Abha, Saudi Arabia
>
> 
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 
_
Filipe Camargo Dalmatti Alves Lima
PhD Student
University of S?o Paulo, Physics Institute, Materials Physics Department,
Nanomol Group, Brazil.
Phones:(11) 3091-6881  (USP)
(11) 97408-2755 (Vivo)
-- next part --
An HTML attachment was scrubbed...
URL: 
http://pwscf.org/pipermail/pw_forum/attachments/20140426/cf248cfd/attachment.html
 

[Pw_forum] Relax calculation

[Sohail Ahmad]

I am using QE 5.0.2 and I have a very basic question.
To optimise the structure of a material, i started with known experimental 
lattice constants and calculated energy vs lattice to know the optimised 
lattice constants.?

Now i wish to apply the strain 

so i increased lattice constant 'a' by 2% (let us say)

now i need to relax (i believe) to get optimised coordinates before proceeding 
further and wish to know force and stress as well.


So my question is i should consider it as 'relax' or "vc relax"
if relax then following should work but unfortunately no

tprnfor = .TRUE.
tstress = .TRUE.
ion_dynamics = 'bfgs'

If i donot consider force and stress, then it gives me final coordinates

Is the above step true in this particular set of problems of strain application 
or should i use variable cell.
i am little confused.

So

?
- 

Sohail AhmadKing Khalid University
Abha, Saudi Arabia


-- next part --
An HTML attachment was scrubbed...
URL: 
http://pwscf.org/pipermail/pw_forum/attachments/20140426/5fe593e1/attachment.html
 

[Pw_forum] Relax Calculation in ZnO

[Duy Le]

Hi Angga,

1. tetrahedra is not a suitable method for force/relaxation...
calculations.
There is no fundamental problem of using smearing for
semi-conductor/insulator. The only problem is it takes a little bit more
time to converge.

2. No. Unless you need some quantities or files that were not calculated or
generated during relaxation.
 
Duy Le
Postdoctoral Associate
Department of Physics
University of Central Florida.
Website: http://www.physics.ucf.edu/~dle


On Thu, Jan 10, 2013 at 3:12 AM, Angga Fauzi wrote:

> Dear all QE users,
>
> I am trying to run relax calculation for my ZnO system. There are
> something I want to ask.
>
>1. In running relax calculation, what occupations should I use? I am
>trying to use occupations = 'tetrahedra', but it doesn't work. I am afraid
>if I use occupations = 'smearing', my result calculation doesn't valid
>since ZnO is a semiconductor, not a metal.
>2. After my relax calculation is done, should I run a scf calculation
>again with atomic positions I get from relax calculation?
>
> My input file is below.
>
>  &CONTROL
>title = 'ZnO' ,
>  calculation = 'relax',
>   outdir = '$TMP_DIR' ,
>   pseudo_dir = '$PSEUDO_DIR' ,
>   prefix = 'ZnO',
>   wf_collect = .true.
>  tprnfor = .true.
>forc_conv_thr = 1.0d-3
>  /
>  &SYSTEM
>ibrav = 4,
>celldm(1) = 12.998 ,
>celldm(3) = 1.625 ,
>  nat = 32,
> ntyp = 2,
>  ecutwfc = 30.0,
>  occupations = 'smearing',
> smearing = 'mv',
>  degauss = 0.02,
>nspin = 2,
>starting_magnetization(1) = 0.0,
>  /
>  &ELECTRONS
>  mixing_beta = 0.62
> conv_thr = 1.0d-3
>  /
>  &IONS
> ion_dynamics = 'bfgs',
>ion_positions = 'default',
>  phase_space = 'full',
>pot_extrapolation = 'atomic',
>wfc_extrapolation = 'none',
> remove_rigid_rot = .false.
>  /
> ATOMIC_SPECIES
>Zn   65.38000  Zn.pbe-van.UPF
> O   15.99900  O.pbe-van_ak.UPF
> ATOMIC_POSITIONS crystal
>Zn  0.166000.333000.0
> O  0.166000.333000.18960
>Zn  0.333000.166000.25000
> O  0.333000.166000.43960
>Zn  0.666000.333000.0
> O  0.666000.333000.18960
>Zn  0.833000.166000.25000
> O  0.833000.166000.43960
>Zn  0.166000.833000.0
> O  0.166000.833000.18960
>Zn  0.333000.666000.25000
> O  0.333000.666000.43960
>Zn  0.666000.833000.0
> O  0.666000.833000.18960
>Zn  0.833000.666000.25000
> O  0.833000.666000.43960
>Zn  0.166000.333000.5
> O  0.166000.333000.68960
>Zn  0.333000.166000.75000
> O  0.333000.166000.93960
>Zn  0.666000.333000.5
> O  0.666000.333000.68960
>Zn  0.833000.166000.75000
> O  0.833000.166000.93960
>Zn  0.166000.833000.5
> O  0.166000.833000.68960
>Zn  0.333000.666000.75000
> O  0.333000.666000.93960
>Zn  0.666000.833000.5
> O  0.666000.833000.68960
>Zn  0.833000.666000.75000
> O  0.833000.666000.93960
> K_POINTS automatic
>   12 12 8   0 0 0
>
> Thank you very much for your attention.
>
> Regards,
> Angga
>
> Angga Dito Fauzi
> Undergraduate Student
> Department of Physics, Faculty of Mathematics and Natural Sciences
> Universitas Indonesia, Depok 16424, Indonesia
> Phone: +628124139348
> Email: angga_dito_fauzi at yahoo.com
>
> ___
> 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://pwscf.org/pipermail/pw_forum/attachments/20130116/56c0831f/attachment.html
 

[Pw_forum] Relax Calculation in ZnO

[Yue-Wen Fang]

The second question: yes, you should use the atomic positions from relax
calculation, that's why we relax the structure.

2013/1/10 Angga Fauzi 

> Dear all QE users,
>
> I am trying to run relax calculation for my ZnO system. There are
> something I want to ask.
>
>1. In running relax calculation, what occupations should I use? I am
>trying to use occupations = 'tetrahedra', but it doesn't work. I am afraid
>if I use occupations = 'smearing', my result calculation doesn't valid
>since ZnO is a semiconductor, not a metal.
>2. After my relax calculation is done, should I run a scf calculation
>again with atomic positions I get from relax calculation?
>
> My input file is below.
>
>  &CONTROL
>title = 'ZnO' ,
>  calculation = 'relax',
>   outdir = '$TMP_DIR' ,
>   pseudo_dir = '$PSEUDO_DIR' ,
>   prefix = 'ZnO',
>   wf_collect = .true.
>  tprnfor = .true.
>forc_conv_thr = 1.0d-3
>  /
>  &SYSTEM
>ibrav = 4,
>celldm(1) = 12.998 ,
>celldm(3) = 1.625 ,
>  nat = 32,
> ntyp = 2,
>  ecutwfc = 30.0,
>  occupations = 'smearing',
> smearing = 'mv',
>  degauss = 0.02,
>nspin = 2,
>starting_magnetization(1) = 0.0,
>  /
>  &ELECTRONS
>  mixing_beta = 0.62
> conv_thr = 1.0d-3
>  /
>  &IONS
> ion_dynamics = 'bfgs',
>ion_positions = 'default',
>  phase_space = 'full',
>pot_extrapolation = 'atomic',
>wfc_extrapolation = 'none',
> remove_rigid_rot = .false.
>  /
> ATOMIC_SPECIES
>Zn   65.38000  Zn.pbe-van.UPF
> O   15.99900  O.pbe-van_ak.UPF
> ATOMIC_POSITIONS crystal
>Zn  0.166000.333000.0
> O  0.166000.333000.18960
>Zn  0.333000.166000.25000
> O  0.333000.166000.43960
>Zn  0.666000.333000.0
> O  0.666000.333000.18960
>Zn  0.833000.166000.25000
> O  0.833000.166000.43960
>Zn  0.166000.833000.0
> O  0.166000.833000.18960
>Zn  0.333000.666000.25000
> O  0.333000.666000.43960
>Zn  0.666000.833000.0
> O  0.666000.833000.18960
>Zn  0.833000.666000.25000
> O  0.833000.666000.43960
>Zn  0.166000.333000.5
> O  0.166000.333000.68960
>Zn  0.333000.166000.75000
> O  0.333000.166000.93960
>Zn  0.666000.333000.5
> O  0.666000.333000.68960
>Zn  0.833000.166000.75000
> O  0.833000.166000.93960
>Zn  0.166000.833000.5
> O  0.166000.833000.68960
>Zn  0.333000.666000.75000
> O  0.333000.666000.93960
>Zn  0.666000.833000.5
> O  0.666000.833000.68960
>Zn  0.833000.666000.75000
> O  0.833000.666000.93960
> K_POINTS automatic
>   12 12 8   0 0 0
>
> Thank you very much for your attention.
>
> Regards,
> Angga
>
> Angga Dito Fauzi
> Undergraduate Student
> Department of Physics, Faculty of Mathematics and Natural Sciences
> Universitas Indonesia, Depok 16424, Indonesia
> Phone: +628124139348
> Email: angga_dito_fauzi at yahoo.com
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>



-- 

Yue-Wen FANG, PhD candidate
Key Laboratory of Polar Materials and Devices, Ministry of
Education
East China Normal University 
Phone: +86-18321726131
I will persist until I succeed!
-- next part --
An HTML attachment was scrubbed...
URL: 
http://pwscf.org/pipermail/pw_forum/attachments/20130113/f1583b5a/attachment-0001.html
 

[Pw_forum] Relax Calculation for ZnO

[Lorenzo Paulatto]

On 10 January 2013 09:01, Angga Fauzi  wrote:

> Dear all QE users,
>
> I am trying to run relax calculation for my ZnO system. There are
> something I want to ask.
>
>1. In running relax calculation, what occupations should I use? I am
>trying to use occupations = 'tetrahedra', but it doesn't work.
>
> What do you mean by "it does not work"? Which symptom make you suspect
that it may not be working?

>
>1. I am afraid if I use occupations = 'smearing', my result
>calculation doesn't valid since ZnO is a semiconductor, not a metal.
>
> If it is not a metal, you can normally use fixed occupations.


>1. After my relax calculation is done, should I run a scf calculation
>again with atomic positions I get from relax calculation?
>
> You only need to for variable cell calculations, and only for code older
that 5.0.

cheers


-- 
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Universit? Paris 6
phone: +33 (0)1 44275 084 / skype: paulatz
www:   http://www-int.impmc.upmc.fr/~paulatto/
mail:  23-24/4?16 Bo?te courrier 115, 4 place Jussieu 75252 Paris C?dex 05
-- next part --
An HTML attachment was scrubbed...
URL: 
http://pwscf.org/pipermail/pw_forum/attachments/20130112/0d98baf6/attachment.html
 

[Pw_forum] Relax Calculation for ZnO

[naz...@iasbs.ac.ir]

> Dear all QE users, 
> 
> I am trying to run relax
calculation for my ZnO system. There are 
> something I want to
ask. 
> 1. In running relax calculation, what occupations should I
use? I am 
> trying to use occupations = 'tetrahedra', but it
doesn't work. I am 
> afraid if I use occupations = 'smearing', my
result calculation doesn't 
> valid since ZnO is a semiconductor,
not a metal.?

? For semiconductor??
occupations=fixed
> 
> 2. After my relax calculation is
done, should I run a scf calculation 
> again with atomic
positions I get from relax calculation??
?
?? For what?
?? 
> I also attach my
input file. Thank you very much for your attention. 
> 
>
Regards, 
> Angga 
> ? 
> Angga Dito Fauzi

> Undergraduate Student 
> Department of Physics, Faculty
of Mathematics and Natural Sciences 
> Universitas Indonesia,
Depok 16424, Indonesia 
> Phone: +628124139348 
> Email:
angga_dito_fauzi at yahoo.com 
> -- 
> This message has been
scanned for viruses and 
> dangerous content by MailScanner, and
is 
> believed to be clean. 
> 
>
___ 
> Pw_forum
mailing list 
> Pw_forum at pwscf.org 
>
http://pwscf.org/mailman/listinfo/pw_forum 


-- 
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.

-- next part --
An HTML attachment was scrubbed...
URL: 
http://pwscf.org/pipermail/pw_forum/attachments/20130110/d6fe8636/attachment.html
 

[Pw_forum] Relax Calculation in ZnO

[Angga Fauzi]

Dear all QE users,

I am trying to run relax calculation for my ZnO system. There are something I 
want to ask.
1. In running relax calculation, what occupations should I use? I am 
trying to use occupations = 'tetrahedra', but it doesn't work. I am afraid if I 
use occupations = 'smearing', my result calculation doesn't valid since ZnO is 
a semiconductor, not a metal.

2. After my relax calculation is done, should I run a scf calculation 
again with atomic positions I get from relax calculation?
My input file is below.

?&CONTROL
? ? ? ? ? ? ? ? ? ? ? ?title = 'ZnO' ,
? ? ? ? ? ? ? ? ?calculation = 'relax',
? ? ? ? ? ? ? ? ? ? ? outdir = '$TMP_DIR' ,
? ? ? ? ? ? ? ? ? pseudo_dir = '$PSEUDO_DIR' ,
? ? ? ? ? ? ? ? ? ? ? prefix = 'ZnO',
? ? ? ? ? ? ? ? ? wf_collect = .true.
? ? ? ? ? ? ? ? ? ? ?tprnfor = .true.
? ? ? ? ? ? ? ?forc_conv_thr = 1.0d-3
?/
?&SYSTEM
? ? ? ? ? ? ? ? ? ? ? ?ibrav = 4,?
? ? ? ? ? ? ? ? ? ?celldm(1) = 12.998 ,
? ? ? ? ? ? ? ? ? ?celldm(3) = 1.625 ,
? ? ? ? ? ? ? ? ? ? ? ? ?nat = 32,
? ? ? ? ? ? ? ? ? ? ? ? ntyp = 2,
? ? ? ? ? ? ? ? ? ? ?ecutwfc = 30.0,
? ? ? ? ? ? ? ? ?occupations = 'smearing',
? ? ? ? ? ? ? ? ? ? smearing = 'mv',
? ? ? ? ? ? ? ? ? ? ?degauss = 0.02,
? ? ? ? ? ? ? ? ? ? ? ?nspin = 2,
? ?starting_magnetization(1) = 0.0,
?/
?&ELECTRONS
? ? ? ? ? ? ? ? ?mixing_beta = 0.62
? ? ? ? ? ? ? ? ? ? conv_thr = 1.0d-3
?/
?&IONS
? ? ? ? ? ? ? ? ion_dynamics = 'bfgs',
? ? ? ? ? ? ? ?ion_positions = 'default',
? ? ? ? ? ? ? ? ?phase_space = 'full',
? ? ? ? ? ?pot_extrapolation = 'atomic',
? ? ? ? ? ?wfc_extrapolation = 'none',
? ? ? ? ? ? remove_rigid_rot = .false.
?/
ATOMIC_SPECIES
? ?Zn ? 65.38000 ?Zn.pbe-van.UPF
? ? O ? 15.99900 ?O.pbe-van_ak.UPF
ATOMIC_POSITIONS crystal?
? ?Zn ? ? ?0.16600 ? ?0.33300 ? ?0.0
? ? O ? ? ?0.16600 ? ?0.33300 ? ?0.18960 ? ?
? ?Zn ? ? ?0.33300 ? ?0.16600 ? ?0.25000?
? ? O ? ? ?0.33300 ? ?0.16600 ? ?0.43960 ? ?
? ?Zn ? ? ?0.66600 ? ?0.33300 ? ?0.0 ? ?
? ? O ? ? ?0.66600 ? ?0.33300 ? ?0.18960 ? ?
? ?Zn ? ? ?0.83300 ? ?0.16600 ? ?0.25000 ? ?
? ? O ? ? ?0.83300 ? ?0.16600 ? ?0.43960 ? ?
? ?Zn ? ? ?0.16600 ? ?0.83300 ? ?0.0 ? ?
? ? O ? ? ?0.16600 ? ?0.83300 ? ?0.18960 ? ?
? ?Zn ? ? ?0.33300 ? ?0.66600 ? ?0.25000 ? ?
? ? O ? ? ?0.33300 ? ?0.66600 ? ?0.43960 ? ?
? ?Zn ? ? ?0.66600 ? ?0.83300 ? ?0.0 ? ?
? ? O ? ? ?0.66600 ? ?0.83300 ? ?0.18960 ? ?
? ?Zn ? ? ?0.83300 ? ?0.66600 ? ?0.25000 ? ?
? ? O ? ? ?0.83300 ? ?0.66600 ? ?0.43960 ? ?
? ?Zn ? ? ?0.16600 ? ?0.33300 ? ?0.5 ? ?
? ? O ? ? ?0.16600 ? ?0.33300 ? ?0.68960 ? ?
? ?Zn ? ? ?0.33300 ? ?0.16600 ? ?0.75000 ? ?
? ? O ? ? ?0.33300 ? ?0.16600 ? ?0.93960 ? ?
? ?Zn ? ? ?0.66600 ? ?0.33300 ? ?0.5
? ? O ? ? ?0.66600 ? ?0.33300 ? ?0.68960 ? ?
? ?Zn ? ? ?0.83300 ? ?0.16600 ? ?0.75000 ? ?
? ? O ? ? ?0.83300 ? ?0.16600 ? ?0.93960 ? ?
? ?Zn ? ? ?0.16600 ? ?0.83300 ? ?0.5 ? ?
? ? O ? ? ?0.16600 ? ?0.83300 ? ?0.68960 ? ?
? ?Zn ? ? ?0.33300 ? ?0.66600 ? ?0.75000 ? ?
? ? O ? ? ?0.33300 ? ?0.66600 ? ?0.93960 ? ?
? ?Zn ? ? ?0.66600 ? ?0.83300 ? ?0.5 ? ?
? ? O ? ? ?0.66600 ? ?0.83300 ? ?0.68960 ? ?
? ?Zn ? ? ?0.83300 ? ?0.66600 ? ?0.75000 ? ?
? ? O ? ? ?0.83300 ? ?0.66600 ? ?0.93960 ? ?
K_POINTS automatic
? 12 12 8 ? 0 0 0

Thank you very much for your attention.

Regards,
Angga
?
Angga Dito Fauzi
Undergraduate Student
Department of Physics, Faculty of Mathematics and Natural Sciences
Universitas Indonesia, Depok 16424, Indonesia
Phone: +628124139348
Email: angga_dito_fauzi at yahoo.com
-- next part --
An HTML attachment was scrubbed...
URL: 
http://pwscf.org/pipermail/pw_forum/attachments/20130110/6bed07df/attachment-0001.html
 

[Pw_forum] Relax Calculation for ZnO

[Angga Fauzi]

Dear all QE users,

I am trying to run relax calculation for my ZnO system. There are something I 
want to ask.
1. In running relax calculation, what occupations should I use? I am 
trying to use occupations = 'tetrahedra', but it doesn't work. I am afraid if I 
use occupations = 'smearing', my result calculation doesn't valid since ZnO is 
a semiconductor, not a metal.

2. After my relax calculation is done, should I run a scf calculation 
again with atomic positions I get from relax calculation?
I also attach my input file. Thank you very much for your attention.

Regards,
Angga
?
Angga Dito Fauzi
Undergraduate Student
Department of Physics, Faculty of Mathematics and Natural Sciences
Universitas Indonesia, Depok 16424, Indonesia
Phone: +628124139348
Email: angga_dito_fauzi at yahoo.com
-- next part --
An HTML attachment was scrubbed...
URL: 
http://pwscf.org/pipermail/pw_forum/attachments/20130110/a286e50e/attachment.html
 
-- next part --
A non-text attachment was scrubbed...
Name: ZnO.relax.in
Type: application/octet-stream
Size: 3122 bytes
Desc: not available
Url : 
http://pwscf.org/pipermail/pw_forum/attachments/20130110/a286e50e/attachment.obj
 

[Pw_forum] relax calculation for some atoms in the structure

[KangYun Song]

Dear Tram:
 You can see the example03, it will help for you.

Yun Song,Kang
Department Physical Science and Technology of  Inner Mongolia University.
 



Date: Wed, 16 Nov 2011 15:07:54 -0700
From: tram...@u.boisestate.edu
To: pw_forum at pwscf.org
Subject: [Pw_forum] relax calculation for some atoms in the structure

Dear QE users,
I'd like to do a relax calculation for only certain atoms in my structrure 
while keeping some other ones fixed, but I have not been able to find out how 
to do so. Would you give me some suggestions? anything would be appreciated.
Regards, 
Tram Bui

M.S. Materials Science & Engineering
trambui at u.boisestate.edu


___ Pw_forum mailing list Pw_forum 
at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum 
   
-- next part --
An HTML attachment was scrubbed...
URL: 
http://www.democritos.it/pipermail/pw_forum/attachments/2017/4bc23b40/attachment.htm
 

[Pw_forum] relax calculation for some atoms in the structure

[Tram Bui]

Dear QE users,
I'd like to do a relax calculation for only certain atoms in my
structrure while keeping some other ones fixed, but I have not been able to
find out how to do so. Would you give me some suggestions? anything would
be appreciated.
Regards,
Tram Bui

M.S. Materials Science & Engineering
trambui at u.boisestate.edu
-- next part --
An HTML attachment was scrubbed...
URL: 
http://www.democritos.it/pipermail/pw_forum/attachments/2016/d3efdf73/attachment.htm
 

[Pw_forum] Relax calculation not converging

[marsa...@democritos.it]

Dear Dimpy, the default value for scf steps is 100. The message means 
that the code does not achieve the electronic convergence after 100 scf 
steps. This usually means that your initial electronic configuration is 
too far from the scf one and the algorithm does not manage to converge 
in 100 step. Or, that there exist "two" solutions and the algorithm is 
oscillating. If it is just a question of been to far there are two 
possibilities 1) the algorithm need just more scf steps, so you just 
need to increase electron_maxstep (default=100) or to decrease 
mixing_beta (or both) (attention the decrease of mixing beta might 
produce that the algorithm need also more electron step). 2) you are 
too far and "two" solutions are accessible. This is for instance what 
happens in SiO2 for the charged -1 and -2 oxygen interstitial, or the 
Si vacancy. For treating such a problem you need to first do a 
pre-relaxation with some trick. For the insterstitial it is better to 
start from a neutral relaxation, for the Si vacancy one need to relax 
first with a substituted Al. Sometimes it can also bee usefull to 
rpe-relax with electronic temperature to facilitate convergence (ad a 
broadening).

hope it can help you, bests

Layla

Quoting Dimpy Sharma :

>
> Hi Quantum espresso users,
>
> I have been trying to perform a relax calculation in my system with 
> 99 atoms (semiconductor system) and I am running my calculation in 48 
> processors. The calculation has finished 3 scf steps and finished 100 
> iterations, but after this it stops and it is showing me the 
> following message .
> ' convergence NOT achieved after 100 iterations: stopping'
>
> I have restart my calculation, still I got the same error message 
> after 100 iteration steps.
>
> Can any body give me any suggestion?
>
> Thanks
>
> Dimpy
>




This message was sent using IMP, the Internet Messaging Program.

[Pw_forum] Relax calculation not converging

[Paolo Giannozzi]

On Oct 9, 2009, at 16:13 , Duy Le wrote:

> 1. Grep total energy of last few iteration, if they are converging,  
> you may change the electron_maxstep to 200, 300, 5000 :)

not a good advice. Self-consistency should converge in less than
100 iterations (and it does, in non-pathological cases)

P.
---
Paolo Giannozzi, Dept of Physics, University of Udine
via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222

[Pw_forum] Relax calculation not converging

[Mighfar Imam]

Convergence might be slow or oscillatory, try changing mixing beta.

mighfar imam
JNCASR, B'lore.
India.


Dimpy Sharma
>
> Hi Quantum espresso users,
>
> I have been trying to perform a relax calculation in my system with 99
> atoms (semiconductor system) and I am running my calculation in 48
> processors. The calculation has finished 3 scf steps and finished 100
> iterations, but after this it stops and it is showing me the following
> message .
> ' convergence NOT achieved after 100 iterations: stopping'
>
> I have restart my calculation, still I got the same error message after
> 100 iteration steps.
>
> Can any body give me any suggestion?
>
> Thanks
>
> Dimpy
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>

[Pw_forum] Relax calculation not converging

[Paolo Giannozzi]

On Oct 9, 2009, at 11:56 , Dimpy Sharma wrote:

> ' convergence NOT achieved after 100 iterations: stopping'
>
please see here:
http://www.quantum-espresso.org/user_guide/ 
node76.html#SECTION00096020

P.
---
Paolo Giannozzi, Dept of Physics, University of Udine
via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222

[Pw_forum] Relax calculation not converging

[Dimpy Sharma]

Hi Quantum espresso users,

I have been trying to perform a relax calculation in my system with 99 atoms 
(semiconductor system) and I am running my calculation in 48 processors. The 
calculation has finished 3 scf steps and finished 100 iterations, but after 
this it stops and it is showing me the following message .
' convergence NOT achieved after 100 iterations: stopping'

I have restart my calculation, still I got the same error message after 100 
iteration steps.

Can any body give me any suggestion?

Thanks

Dimpy
-- next part --
An HTML attachment was scrubbed...
URL: 
http://www.democritos.it/pipermail/pw_forum/attachments/20091009/1191e362/attachment.htm
 

[Pw_forum] Relax calculation not converging

[Duy Le]

If it is not converged, and you restart it again without any modification
(or dirty trick), it should not be converged.
1. Grep total energy of last few iteration, if they are converging, you may
change the electron_maxstep to 200, 300, 5000 :) or you may increase the
conv_th (after getting the relaxed structure, restart the calculation with
new structure and read the potential, wavefunction, lower the conv_th...)
2. Play with Mixing_mode and mixing_beta
3. Change diagonalization

--
Duy Le
PhD Student
Department of Physics
University of Central Florida.


On Fri, Oct 9, 2009 at 9:59 AM, Huolin Xin  wrote:

> For such big unit cells, even Gamma point should work, right?
>
>
> On Fri, Oct 9, 2009 at 7:02 AM, Ary Junior  wrote:
>
>> Did you make any convergence tests for ecut? The set of PW that you are
>> using is enough? And about your k-points sample?
>>
>> []
>>
>> Ary Junior
>>
>>
>> On Fri, Oct 9, 2009 at 7:38 AM, Mighfar Imam wrote:
>>
>>> Convergence might be slow or oscillatory, try changing mixing beta.
>>>
>>> mighfar imam
>>> JNCASR, B'lore.
>>> India.
>>>
>>>
>>> Dimpy Sharma
>>> >
>>> > Hi Quantum espresso users,
>>> >
>>> > I have been trying to perform a relax calculation in my system with 99
>>> > atoms (semiconductor system) and I am running my calculation in 48
>>> > processors. The calculation has finished 3 scf steps and finished 100
>>> > iterations, but after this it stops and it is showing me the following
>>> > message .
>>> > ' convergence NOT achieved after 100 iterations: stopping'
>>> >
>>> > I have restart my calculation, still I got the same error message after
>>> > 100 iteration steps.
>>> >
>>> > Can any body give me any suggestion?
>>> >
>>> > Thanks
>>> >
>>> > Dimpy
>>> > ___
>>> > Pw_forum mailing list
>>> > Pw_forum at pwscf.org
>>> > http://www.democritos.it/mailman/listinfo/pw_forum
>>> >
>>>
>>> ___
>>> Pw_forum mailing list
>>> Pw_forum at pwscf.org
>>> http://www.democritos.it/mailman/listinfo/pw_forum
>>>
>>
>>
>>
>> --
>> http://lattes.cnpq.br/8221674673413336
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>>
>>
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
-- next part --
An HTML attachment was scrubbed...
URL: 
http://www.democritos.it/pipermail/pw_forum/attachments/20091009/bd5a92a3/attachment.htm
 

[Pw_forum] Relax calculation not converging

[Huolin Xin]

For such big unit cells, even Gamma point should work, right?

On Fri, Oct 9, 2009 at 7:02 AM, Ary Junior  wrote:

> Did you make any convergence tests for ecut? The set of PW that you are
> using is enough? And about your k-points sample?
>
> []
>
> Ary Junior
>
>
> On Fri, Oct 9, 2009 at 7:38 AM, Mighfar Imam  wrote:
>
>> Convergence might be slow or oscillatory, try changing mixing beta.
>>
>> mighfar imam
>> JNCASR, B'lore.
>> India.
>>
>>
>> Dimpy Sharma
>> >
>> > Hi Quantum espresso users,
>> >
>> > I have been trying to perform a relax calculation in my system with 99
>> > atoms (semiconductor system) and I am running my calculation in 48
>> > processors. The calculation has finished 3 scf steps and finished 100
>> > iterations, but after this it stops and it is showing me the following
>> > message .
>> > ' convergence NOT achieved after 100 iterations: stopping'
>> >
>> > I have restart my calculation, still I got the same error message after
>> > 100 iteration steps.
>> >
>> > Can any body give me any suggestion?
>> >
>> > Thanks
>> >
>> > Dimpy
>> > ___
>> > Pw_forum mailing list
>> > Pw_forum at pwscf.org
>> > http://www.democritos.it/mailman/listinfo/pw_forum
>> >
>>
>> ___
>> Pw_forum mailing list
>> Pw_forum at pwscf.org
>> http://www.democritos.it/mailman/listinfo/pw_forum
>>
>
>
>
> --
> http://lattes.cnpq.br/8221674673413336
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>
>
-- next part --
An HTML attachment was scrubbed...
URL: 
http://www.democritos.it/pipermail/pw_forum/attachments/20091009/d1e55813/attachment-0001.htm
 

[Pw_forum] Relax calculation not converging

[Ary Junior]

Did you make any convergence tests for ecut? The set of PW that you are
using is enough? And about your k-points sample?

[]

Ary Junior

On Fri, Oct 9, 2009 at 7:38 AM, Mighfar Imam  wrote:

> Convergence might be slow or oscillatory, try changing mixing beta.
>
> mighfar imam
> JNCASR, B'lore.
> India.
>
>
> Dimpy Sharma
> >
> > Hi Quantum espresso users,
> >
> > I have been trying to perform a relax calculation in my system with 99
> > atoms (semiconductor system) and I am running my calculation in 48
> > processors. The calculation has finished 3 scf steps and finished 100
> > iterations, but after this it stops and it is showing me the following
> > message .
> > ' convergence NOT achieved after 100 iterations: stopping'
> >
> > I have restart my calculation, still I got the same error message after
> > 100 iteration steps.
> >
> > Can any body give me any suggestion?
> >
> > Thanks
> >
> > Dimpy
> > ___
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >
>
> ___
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://www.democritos.it/mailman/listinfo/pw_forum
>



-- 
http://lattes.cnpq.br/8221674673413336
-- next part --
An HTML attachment was scrubbed...
URL: 
http://www.democritos.it/pipermail/pw_forum/attachments/20091009/f543d972/attachment.htm
 

[Pw_forum] Relax calculation in quantum espresso with 56 atoms had not been converged

[Michael Sullivan]

You may have set nstep to 40. If you are using BFGS, it could be that it 
actually took 50 steps (the default, I think) but it only used the last 39 
steps. Have a look at the energies and see how it looks by using a grep command 
like this:
grep "!total energy " 

If you add -c to grep then it should give you the number of optimization steps 
it took.

If this isn't the case, then you'll need to share more information and it could 
be an issue with your computer.

Mike
michael at ihpc.a-star.edu.sg
http://www.sullivan.sg/

From: pw_forum-bounces at pwscf.org [mailto:pw_forum-boun...@pwscf.org] On 
Behalf Of Shaptrishi Sharma
Sent: Wednesday, August 19, 2009 9:55 PM
To: pw_forum at pwscf.org
Subject: Re: [Pw_forum] Pw_forum Digest, Vol 26, Issue 52

Hi Mike,

Thansk for your help, well I cannot understand your this point "Only allowed 40 
optimization steps." How do we know that the optimisation steps are 40 and why??

Thanks

SS
My two guesses are:

(1) Ran out of time in the queue.
(2) Only allowed 40 optimization steps.

That said, we need more information. Usually something will show up in the 
error file that will give us a hint.

Mike
michael at ihpc.a-star.edu.sg
http://www.sullivan.sg/

From: pw_forum-bounces at pwscf.org [mailto:pw_forum-boun...@pwscf.org] On 
Behalf Of Shaptrishi Sharma
Sent: Wednesday, August 19, 2009 5:13 PM
To: pw_forum at pwscf.org
Subject: [Pw_forum] Relax calculation in quantum espresso with 56 atoms had not 
been converged

Hi ,

I have submitted one relax calculation for 56 atoms in quantum espresso , 
however after 39 iterations it stops without any further informations, nor even 
a CRASH file. So any body can suggest me what the possible reason?

Thanks
SS

This email is confidential and may be privileged. If you are not the intended 
recipient, please delete it and notify us immediately. Please do not copy or 
use it for any purpose, or disclose its contents to any other person. Thank you.
___
Pw_forum mailing list
Pw_forum at pwscf.org
http://www.democritos.it/mailman/listinfo/pw_forum


This email is confidential and may be privileged. If you are not the intended 
recipient, please delete it and notify us immediately. Please do not copy or 
use it for any purpose, or disclose its contents to any other person. Thank you.

[Pw_forum] Relax calculation in quantum espresso with 56 atoms had not been converged

[Michael Sullivan]

My two guesses are:

(1) Ran out of time in the queue.
(2) Only allowed 40 optimization steps.

That said, we need more information. Usually something will show up in the 
error file that will give us a hint.

Mike
michael at ihpc.a-star.edu.sg
http://www.sullivan.sg/

From: pw_forum-bounces at pwscf.org [mailto:pw_forum-boun...@pwscf.org] On 
Behalf Of Shaptrishi Sharma
Sent: Wednesday, August 19, 2009 5:13 PM
To: pw_forum at pwscf.org
Subject: [Pw_forum] Relax calculation in quantum espresso with 56 atoms had not 
been converged

Hi ,

I have submitted one relax calculation for 56 atoms in quantum espresso , 
however after 39 iterations it stops without any further informations, nor even 
a CRASH file. So any body can suggest me what the possible reason?

Thanks
SS

This email is confidential and may be privileged. If you are not the intended 
recipient, please delete it and notify us immediately. Please do not copy or 
use it for any purpose, or disclose its contents to any other person. Thank you.

[Pw_forum] Relax calculation in quantum espresso with 56 atoms had not been converged

[Lorenzo Paulatto]

In data 19 agosto 2009 alle ore 11:13:28, Shaptrishi Sharma  
 ha scritto:
> even a CRASH file. So any body can suggest me what the possible reason?

Dear Shaptrishi,
you need to provide more detail if you want a meaningful answer. At least  
the last 500 lines of job's output.

best regards



-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/

 *** save italian brains ***
  http://saveitalianbrains.wordpress.com/

[Pw_forum] Relax calculation in quantum espresso with 56 atoms had not been converged

[Shaptrishi Sharma]

Hi ,

I have submitted one relax calculation for 56 atoms in quantum espresso ,
however after 39 iterations it stops without any further informations, nor
even a CRASH file. So any body can suggest me what the possible reason?

Thanks
SS
-- next part --
An HTML attachment was scrubbed...
URL: 
http://www.democritos.it/pipermail/pw_forum/attachments/20090819/ebdd6803/attachment.htm