[Wannier] Dissimilar results in band structures for a system obtained from Wannier90

Nicola Marzari nicola.marzari at epfl.ch
Thu Jun 25 21:17:18 CEST 2015



Dear Seyed,


any news on this?

			nicola



On 15/06/2015 14:17, Nicola Marzari wrote:
>
> Thanks.
>
> At first sight the two espresso codes give the same eigenvalues in the
> nscf,
> but being run with two different parallelization choices, the
> phases of the wannier functions will all be different, so
> it's like dealing with two independent calculations. So the question is
> for Wannier - to see if you have converged to the correct localized state,
> or not. Usually, if the projections are correct, it shouldn't matter, but
> maybe in this case they are not correct, and hten the codes randomly
> converges, or not.
>
> One of the outputs records a large imaginary part - that's a bad sign.
> The other has two much less localized wavefunctions - maybe good, maybe
> bad.
>
> Can you try with projections that have a s orbital at every atom, and
> a s orbital at every bond? Those should work, and it would be nice
> to see that both codes give the same results.
>
> Otherwise, we'll need to dig deeper.
>
>              nicola
>
>
>
>
> On 15/06/2015 13:41, Seyed Mojtaba Rezaei Sani wrote:
>> Hi Nicola
>>
>> Thanks a lot for your kind response. Surely I did checked outputs before
>> too. There was no considerable difference between them and also there is
>> no unconverged band message. So I can say:
>>
>> Re 1) Every thing works perfectly both in 5.1 and 5.1.2 versions except
>> the disappointing obtained wannier90 band structure by the later.
>> Re 2) No difference.
>>
>> As more details, please find all in/output files for both versions
>> (except UNK ones which are too big) here:
>>
>> https://www.dropbox.com/sh/xhd3etb6zfz2e7c/AAClTpe-aGkwXVrzDcIq6L7Aa?dl=0
>>
>> Thanks again,
>>
>> On Mon, Jun 15, 2015 at 12:23 PM, Nicola Marzari <nicola.marzari at epfl.ch
>> <mailto:nicola.marzari at epfl.ch>> wrote:
>>
>>
>>
>>     Hi Sani,
>>
>>
>>     I had mentioned in my email that you should check both
>>     your input and your output files - since the problems seem due
>>     to the change in version of quantum-espresso (I do appreciate you
>>     did check your input files, but I do wonder why you didn't
>>     read the email in full, since it was asking about the output).
>>
>>     So - do you see any difference in the output files of quantum
>> espresso?
>>
>>      From your plots my first guess would be that you have some states
>> that
>>     are not converged at some k-point.
>>
>>     1) can you confirm that in an older version of QE everything
>>     worked perfectly (*which one*?, and in 5.1.2 you have the problems
>>     below?
>>
>>     2) do the outputs in the two cases differ - for the QE runs, and
>> for the
>>     wannier runs, when run with *identical* inputs? If so, in what do
>>     they differ.
>>
>>     Let us know re 1) and 2) - thanks a lot,
>>
>>                              nicola
>>
>>
>>
>>     On 15/06/2015 09:40, Seyed Mojtaba Rezaei Sani wrote:
>>
>>         Dear all
>>
>>         I am looking forward to receive any kind help.
>>
>>         On Wed, Jun 10, 2015 at 2:59 PM, Seyed Mojtaba Rezaei Sani
>>         <s.m.rezaeisani at gmail.com <mailto:s.m.rezaeisani at gmail.com>
>>         <mailto:s.m.rezaeisani at gmail.com
>>         <mailto:s.m.rezaeisani at gmail.com>>> wrote:
>>
>>              Dear Prof. Marzari
>>
>>              As you suggested I checked input files and they were exactly
>>              identical. but the difference in result remains.
>>              I tried to make a change in calculations so I increased
>>         number of
>>              kpoints in non scf and wannier calculations from
>>              a mesh of 12*12*1 to 16*16*1. The result was an improvement
>>         in band
>>              structure. you can find the plot attached. But
>>              there are still some inadequacies to the pw band in the
>>         region gamma
>>              to X.
>>              Again I increased the grid to a 24*24*1 mesh which
>>         encountered this
>>              error:
>>
>>              Unable to satisfy B1 with any of the first  12 shells
>>                Your cell might be very long, or you may have an
>>         irregular MP grid
>>                Try increasing the parameter search_shells in the win
>>         file (default=12)
>>
>>              Setting the parameter search_shells = 60 solved the problem
>>         but now
>>              inadequacies are in the region S to Y (the plot is
>> attached).
>>              I don't know if there is any parameter that I could change
>>         to solve
>>              this problem. Please give me any probable hint.
>>              Thanks,
>>
>>              On Wed, Jun 10, 2015 at 2:53 PM, Seyed Mojtaba Rezaei Sani
>>              <s.m.rezaeisani at gmail.com <mailto:s.m.rezaeisani at gmail.com>
>>         <mailto:s.m.rezaeisani at gmail.com
>>         <mailto:s.m.rezaeisani at gmail.com>>> wrote:
>>
>>                  Dear Prof. Marzari
>>
>>                  As you suggested I checked input files and they were
>>         exactly
>>                  identical. but the difference in result remains.
>>                  I tried to make a change in calculations so I increased
>>         number
>>                  of kpoints in non scf and wannier calculations from
>>                  a mesh of 12*12*1 to 16*16*1. The result was an
>>         improvement in
>>                  band structure. you can find the plot attached. But
>>                  there are still some inadequacies to the pw band in the
>>         region
>>                  gamma to X.
>>                  Again I increased the grid to a 24*24*1 mesh which
>>         encountered
>>                  this error:
>>
>>                  Unable to satisfy B1 with any of the first  12 shells
>>                    Your cell might be very long, or you may have an
>>         irregular MP grid
>>                    Try increasing the parameter search_shells in the win
>>         file (default=12)
>>
>>                  Setting the parameter search_shells = 60 solved the
>>         problem but
>>                  now inadequacies are in the region S to Y (the plot is
>>         attached).
>>                  I don't know if there is any parameter that I could
>>         change to
>>                  solve this problem. Please give me any probable hint.
>>                  Thanks,
>>
>>                  On Thu, May 28, 2015 at 12:39 PM, Nicola Marzari
>>                  <nicola.marzari at epfl.ch <mailto:nicola.marzari at epfl.ch>
>>         <mailto:nicola.marzari at epfl.ch <mailto:nicola.marzari at epfl.ch>>>
>>         wrote:
>>
>>
>>
>>                      Well, the obvious thing to do is making sure your
>>                      inputs are exactly identical, you re-run the
>>         calculations
>>                      to make sure the error shows up again, and then you
>>         start
>>                      doing a diff in the output files of
>>         quantum-espresso, and
>>                      see where there is a difference.
>>
>>                                                       nicola
>>
>>
>>
>>
>>                      On 28/05/2015 09:07, Seyed Mojtaba Rezaei Sani
>> wrote:
>>
>>                          Dear Wannier90 users,
>>
>>                          I am trying to calculate wannier functions for
>>                          phosphorene using
>>                          wannier90. first I tried to plot band structure
>>         using both
>>                          quantum-espresso and wannier90. Results were in
>>         good
>>                          agreement. Now I
>>                          have upgraded espresso to 5.1.2 version but
>>         with the
>>                          same inputs the
>>                          obtained results are not similar.
>>                          All files are attached and here in .win input:
>>
>>                          num_bands        = 10
>>                          num_wann         = 10
>>                          num_iter         = 500
>>
>>                          Begin Unit_Cell_Cart
>>                          Bohr
>>                                6.282237122     0.000000000
>> 0.0000000000
>>                                0.000000000     8.651074073
>> 0.0000000000
>>                                0.000000000     0.000000000
>> 26.456165734
>>                          End Unit_Cell_Cart
>>
>>                          Begin Atoms_Frac
>>                          P1        0.010000000   0.086656382
>> 0.152592466
>>                          P1        0.010000000   0.913343530
>> 0.001000000
>>                          P2        0.510000000   0.413343618
>> 0.152592466
>>                          P2        0.510000000   0.586656470
>> 0.001000000
>>                          End Atoms_Frac
>>
>>                          Begin Projections
>>                          P1:sp3
>>                          P2:py
>>                          End Projections
>>
>>                          bands_plot = true
>>
>>                          begin kpoint_path
>>                          G 0.0000 0.0000 0.0000 X 0.5000 0.0000 0.0000
>>                          x 0.5000 0.0000 0.0000 S 0.5000 0.5000 0.0000
>>                          S 0.5000 0.5000 0.0000 Y 0.0000 0.5000 0.0000
>>                          Y 0.0000 0.5000 0.0000 G 0.0000 0.0000 0.0000
>>                          end kpoint_path
>>
>>                          mp_grid = 12 12 1
>>
>>                          begin kpoints
>>                              0.00000000  0.00000000  0.00000000
>>                             .
>>                             .
>>                             .
>>                              0.91666667  0.91666667  0.00000000
>>                          End Kpoints
>>
>>                          I would greatly appreciate it if you kindly
>>         give me some
>>                          hints.
>>
>>                          Best regards,
>>
>>                          --
>>                          Seyed Mojtaba Rezaei Sani
>>
>>                          Institute for Research in Fundamental Sciences
>>         (IPM)
>>                          School of Nano-Science
>>                          Shahid Farbin Alley
>>                          Shahid Lavasani st
>>                          P.O. Box 19395-5531
>>                          Tehran, Iran
>>                          Tel: +98 21 2310  (3069)
>>
>>
>>                          _______________________________________________
>>                          Wannier mailing list
>>         Wannier at quantum-espresso.org
>> <mailto:Wannier at quantum-espresso.org>
>>                          <mailto:Wannier at quantum-espresso.org
>>         <mailto:Wannier at quantum-espresso.org>>
>>
>>         http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier
>>
>>
>>                      --
>>
>>
>>
>> ----------------------------------------------------------------------
>>                      Prof Nicola Marzari, Chair of Theory and
>> Simulation of
>>                      Materials, EPFL
>>                      Director, National Centre for Competence in
>>         Research NCCR
>>                      MARVEL, EPFL
>>
>>
>>
>>
>>                  --
>>                  Seyed Mojtaba Rezaei Sani
>>
>>                  Institute for Research in Fundamental Sciences (IPM)
>>                  School of Nano-Science
>>                  Shahid Farbin Alley
>>                  Shahid Lavasani st
>>                  P.O. Box 19395-5531
>>                  Tehran, Iran
>>                  Tel: +98 21 2310  (3069)
>>
>>
>>
>>
>>              --
>>              Seyed Mojtaba Rezaei Sani
>>
>>              Institute for Research in Fundamental Sciences (IPM)
>>              School of Nano-Science
>>              Shahid Farbin Alley
>>              Shahid Lavasani st
>>              P.O. Box 19395-5531
>>              Tehran, Iran
>>              Tel: +98 21 2310  (3069)
>>
>>
>>
>>
>>         --
>>         Seyed Mojtaba Rezaei Sani
>>
>>         Institute for Research in Fundamental Sciences (IPM)
>>         School of Nano-Science
>>         Shahid Farbin Alley
>>         Shahid Lavasani st
>>         P.O. Box 19395-5531
>>         Tehran, Iran
>>         Tel: +98 21 2310  (3069)
>>
>>
>>     --
>>
>>
>> ----------------------------------------------------------------------
>>     Prof Nicola Marzari, Chair of Theory and Simulation of Materials,
>> EPFL
>>     Director, National Centre for Competence in Research NCCR MARVEL,
>> EPFL
>>
>>
>>
>>
>> --
>> Seyed Mojtaba Rezaei Sani
>>
>> Institute for Research in Fundamental Sciences (IPM)
>> School of Nano-Science
>> Shahid Farbin Alley
>> Shahid Lavasani st
>> P.O. Box 19395-5531
>> Tehran, Iran
>> Tel: +98 21 2310  (3069)
>

-- 

----------------------------------------------------------------------
Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL
Director, National Centre for Competence in Research NCCR MARVEL, EPFL



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