[Wannier] Dissimilar results in band structures for a system obtained from Wannier90
Aron Szabo
szaboa at iis.ee.ethz.ch
Mon Jun 29 10:52:12 CEST 2015
Dear Seyed,
I've managed to get nicely converged Wannier functions for phosphorene
by using sp3 projections on each 4 atoms, therefore including 6
conduction bands in the calculation too with the disentanglement method.
The largest spread was 2 A^2. In my experience it should not be much
larger than 3 A^2 for most semiconductors. And the imaginary part of the
Hamiltonian should be practically 0 everywhere (or in the order of
magnitude of 1e-6). I was using 21x21x1 k points. I did not check with
an even mesh, but sometimes it matters a lot for the wannierization
whether you use even or odd mesh. I've used VASP, and I'm not an expert
with espresso, and I did not look into you input and output files. Just
wanted share my experience with phosphorene.
Best,
Aron
On 06/29/2015 09:38 AM, Seyed Mojtaba Rezaei Sani wrote:
> Dear Nicola,
>
> Thanks. Phosphorene has four P atoms in its unit cell so considering
> 10 valence bands and therefore 10 WFs, we can't fit a projection of s
> orbital on every atom and bond to this number.
> But I have found new thing. Instead of increasing the number of
> kpoints in wannier input, I chose a coarser grid which seems to be
> fine enough to provide converged WFs with both versions of codes. The
> resulted band structure completely matches the PWscf one but there is
> an error in transport section implies that there are 0 unit cells and
> Wfs inside the principal layer:
>
> *---------------------------------------------------------------------------*
> | TRANSPORT |
> *---------------------------------------------------------------------------*
>
>
> Calculation of Quantum Conductance and DoS: bulk mode
>
> Maximum imaginary part of the real-space Hamiltonian: 0.189159
>
> ------------------------------------------------------------------------------
> Maximum real part of the real-space Hamiltonian at each lattice point
> --------------------------------------------------------------
> Lattice point R Max |H_ij(R)|
> -1 0.000000
> 0 7.773991
> 1 0.000000
> --------------------------------------------------------------
>
> Number of unit cells inside the principal layer: 0
> Number of Wannier Functions inside the principal layer: 0
>
> Calculating quantum conductance and density of states...
> ERROR: IN ZGESV IN tran_transfer, INFO= -4
> Exiting.......
> tran_transfer: problem in ZGESV 1
>
>
>
> in/output files are attached. Any help would be greatly appreciated.
> I have a stupid question too, What are the satisfying values for the
> imaginary part and spread of WFs?
>
>
>
> On Thu, Jun 25, 2015 at 11:47 PM, Nicola Marzari
> <nicola.marzari at epfl.ch <mailto:nicola.marzari at epfl.ch>> wrote:
>
>
>
> 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>
> <mailto: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>>
> <mailto: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>>
> <mailto: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>>
> <mailto: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)
>
>
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> <mailto:Wannier at quantum-espresso.org>
> <mailto:Wannier at quantum-espresso.org
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>
> <mailto: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
>
>
>
>
> --
> 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
> http://mailman.qe-forge.org/cgi-bin/mailman/listinfo/wannier
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