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

Nicola Marzari nicola.marzari at epfl.ch
Mon Jun 15 09:53:16 CEST 2015



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>> 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>> 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>> 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>
>                 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



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