[Pw_forum] Convergence of relax of slab calculation
ben liew
liewkienben at gmail.com
Wed Aug 5 10:46:49 CEST 2015
Dear Bahadir,
Thanks for your comments. I will try using a lower mixing_beta and change
the mixing_mode='local-TF'.
Dear Ari Paavo Seitsonen,
Thanks. I have no knowledge on the magnetism of my system. How could I know
what value of starting_magnetization that I should use in my slab
calculation? Does the starting_magnetization affect the convergence of my
calculation?
Thank you
Best Regards,
*Ben Liew*
Ph.D Student
Fuel Cell Institute,
The National University of Malaysia,
43600 Bangi,
Selangor, Malaysia.
Contact no. : +6016 552 0878
Email : liewkienben at gmail.com
On Wed, Aug 5, 2015 at 5:20 PM, Bahadır salmankurt <bsalmankurt at gmail.com>
wrote:
> Dear Ari P Seitsonen,
>
> I didnt know that mixing_mode='local-TF' effect initial magnetic moments.
> thanks for this. By the way, Do you know about e field configuration? for
> example, for slab + molecule systems whose atomic positions are in 0.5 and
> 0.65 along z direction , respectively, what must values of the emaxpos
> and eopreg be?
>
> Bests
> Bahadir
>
> 2015-08-05 10:59 GMT+03:00 Ari P Seitsonen <Ari.P.Seitsonen at iki.fi>:
>
>>
>> Dear Ben Liew,
>>
>> Without looking at the structure itself, adding to the previous comment
>> about the algorithm for mixing, you have not really given any initial
>> magnetic moments even if you have 'nspin = 2': The
>> 'starting_magnetization(1) = 0.0' does not give any preferential spin
>> ordering. Do you know something about this, is the system expected to be
>> ferromagnetic, antiferromagnetic, ...?
>>
>> Tiny issues, I usually do the first calculation without the surface
>> dipole as it makes the convergence always a bit trickier; and your
>> 'B ~= 2 * A', but you give the same number of k points in both
>> directions. (I usually tend to use smearing schemes where the occupations
>> are guaranteed to be in the physical range of [0:1], but this is just a
>> personal preference and should thus be ignored)
>>
>> Greetings,
>>
>> apsi
>>
>>
>> -=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-=*=-
>> Ari Paavo Seitsonen / Ari.P.Seitsonen at iki.fi / http://www.iki.fi/~apsi/
>> Ecole Normale Supérieure (ENS), Département de Chimie, Paris
>> Mobile (F) : +33 789 37 24 25 (CH) : +41 79 71 90 935
>>
>>
>>
>> On Wed, 5 Aug 2015, ben liew wrote:
>>
>> Dear PWSCF users,
>>>
>>> Hi, I am a new user of Pwscf. I am working on slab calculation for
>>> pyrolusite MnO2 (110) surface with 3 atomic layers calculation and fixed
>>> bottom 2 layers and only top atomic
>>> layer is allowed to be relaxed. I have also include the dipole
>>> correction for the calculation to counteract with the interaction between
>>> slabs. However, my calculation doesn't
>>> seems to be converged as the scf accuracy is not decreasing over each
>>> iteration. Below is the estimated scf accuracy after hundreds of
>>> iterations, it is not converging
>>>
>>> estimated scf accuracy < 373.64728976 Ry
>>> estimated scf accuracy < 106.52177156 Ry
>>> estimated scf accuracy < 96.97567125 Ry
>>> estimated scf accuracy < 207.03807187 Ry
>>> estimated scf accuracy < 132.53045831 Ry
>>> estimated scf accuracy < 77.19101827 Ry
>>> estimated scf accuracy < 112.41885075 Ry
>>> estimated scf accuracy < 93.27430429 Ry
>>> estimated scf accuracy < 116.68049786 Ry
>>> estimated scf accuracy < 587.09711027 Ry
>>> estimated scf accuracy < 374.45312501 Ry
>>> estimated scf accuracy < 106.89811469 Ry
>>> estimated scf accuracy < 96.84898888 Ry
>>> estimated scf accuracy < 207.83006869 Ry
>>> estimated scf accuracy < 132.74588293 Ry
>>> estimated scf accuracy < 77.09445200 Ry
>>> estimated scf accuracy < 112.41688597 Ry
>>> estimated scf accuracy < 93.57796273 Ry
>>> estimated scf accuracy < 116.25663912 Ry
>>> estimated scf accuracy < 587.39968959 Ry
>>> estimated scf accuracy < 374.91438307 Ry
>>> estimated scf accuracy < 106.71641516 Ry
>>> estimated scf accuracy < 96.75392736 Ry
>>>
>>> I have include my input file as followed. Can anyone tell me is that any
>>> problem with my input file?
>>>
>>> &control
>>> calculation = 'relax'
>>> tstress=.true.
>>> tprnfor=.true.
>>> pseudo_dir='/home/ben/Downloads/espresso-5.1.2/pseudo'
>>> outdir='./vc3'
>>> prefix='pyrolusite'
>>> tefield=.true.
>>> dipfield=.true.
>>> /
>>> &system
>>> ibrav=8,
>>> A=2.8563, B=6.2199, C=20.0
>>> nat=18, ntyp=2,
>>> starting_magnetization(1)=0.0
>>> nspin=2
>>> ecutwfc=37.0
>>> ecutrho=250.0
>>> occupations='smearing'
>>> smearing='m-v'
>>> degauss=0.01
>>> edir=3
>>> emaxpos=0.5
>>> eopreg=0.1
>>> eamp=0.001
>>> /
>>> &electrons
>>> electron_maxstep=500
>>> conv_thr=1.0d-6
>>> mixing_beta=0.7
>>> /
>>> &ions
>>> ion_dynamics='bfgs'
>>> /
>>> ATOMIC_SPECIES
>>> Mn 54.9380 Mn.pbe-spn-kjpaw_psl.0.3.1.UPF
>>> O 15.9994 O.pbe-kjpaw.UPF
>>> ATOMIC_POSITIONS (angstrom)
>>> O 1.428129 3.109734 0.000000 0 0 0
>>> O 1.428129 0.000241 0.652526 0 0 0
>>> Mn 1.428129 3.109896 1.883398 0 0 0
>>> O 0.000000 1.885646 1.883398 0 0 0
>>> O 0.000000 4.334118 1.883398 0 0 0
>>> Mn 0.000000 0.000062 1.883398 0 0 0
>>> O 0.000000 5.014614 4.987475 0 0 0
>>> O 0.000000 1.205401 4.987475 0 0 0
>>> Mn 0.000000 3.109816 4.987475 0 0 0
>>> Mn 1.428129 0.000027 4.987475 0 0 0
>>> O 1.428129 3.109734 3.767387 0 0 0
>>> O 1.428129 0.000241 3.114269 0 0 0
>>> O 1.428129 3.109734 6.207560
>>> O 1.428129 0.000241 6.860698
>>> Mn 1.428129 3.109896 8.091569
>>> O 0.000000 1.885646 8.091569
>>> O 0.000000 4.334118 8.091569
>>> Mn 0.000000 0.000062 8.091569
>>> K_POINTS (automatic)
>>> 5 5 1 0 0 0
>>>
>>> Your comments and suggestion is much appreciated.Thank you.
>>>
>>>
>>> Best Regards,
>>> Ben Liew
>>> Ph.D Student
>>> Fuel Cell Institute,
>>> The National University of Malaysia,
>>> 43600 Bangi,
>>> Selangor, Malaysia.
>>> Contact no. : +6016 552 0878
>>> Email : liewkienben at gmail.com
>>>
>>>
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