Re: [Wien] Constrained DFT for excited state calculations

[Guoping Zhang]

 Dear Dr. Hashemifar,

My answer might be slightly too late, but might be of some help to you. You
can take a look at our papers J. Phys.: Condens. Matter 27 (2015) 206003
(7pp) and Journal of Magnetism and Magnetic Materials 563 (2022) 169885.
This can be done.

Our implementation is to change  the lapw2 codes so that the weightfile
read into the code is  replaced by your desired weight file. There are
three places that Wien code reads in the same weight files. I did not
change the latest codes.  When you try to fill some conduction bands and
remove some electrons from valence bands, give some broadening because the
self-consistent iteration at the next step may have a strong charge
fluctuation, which affects convergence. We tested both statically and
dynamically with a laser pulse, and found Wien2k is very stable. If
necessary, reducing the mixing in case.inm file. Sometimes, we also reduce
the convergence criterion, which must be checked carefully.

Best wishes,

Guoping



On Wed, Jun 14, 2023 at 2:34 PM Seyed Javad Hashemifar 
wrote:

> sounds interesting, thank you!
> ---
> --
> S. Javad Hashemifar, PhD
> Professor, Department of Physics
> Isfahan University of Technology, Iran
> Personal web page: https://hashemifar.iut.ac.ir
>
>
> On 2023-06-14 19:56, Peter Blaha wrote:
>
> It depends, but when you are lucky and have a reasonable gap: yes.
>
> modify case.in2  and reduce NE by one.
>
> copy case.in1 to case.in1sc, and the same with case.in2
>
> edit case.in2sc and increase NE by 2 (by one of the original) and put Emin
> to the previous (scf)  EFermi.
>
> run_lapw ...
>
> In this way you get two densities, one of NE-1 electrons and one with 1
> electron.
>
> However, EF may change and you may have to adapt Emin during this scf
> cycle.
>
> One would need to change the code and read a NBAND_min, 
>
> PS: I tried this once but failed, because I wanted to occupy the "LUMO"
> state, which was of p-y character. My hope was, that this would lead to
> forces and move the atom somewhere else. However, during occupation of this
> py state it got shifted up in energy and another orbital became the "LUMO",
> so my relaxation was not due to this additional py electron, but something
> else 
>
>
> Am 14.06.2023 um 17:09 schrieb Seyed Javad Hashemifar:
>
> Dear Wien2k developers and users
>
> Is  Wien2k able to perform constrained DFT calculations for excited states
> study?
>
> More specifically, I want to empty the Nth state and occupy the (N+1)th
> level.
>
> Bests
>
> S. Javad Hashemifar
>
>
> --
> --
> S. Javad Hashemifar, PhD
> Professor, Department of Physics
> Isfahan University of Technology, Iran
> Personal web page: https://hashemifar.iut.ac.ir
>
>
> ___
> Wien mailing 
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>
> --
> ---
> Peter Blaha,  Inst. f. Materials Chemistry, TU Vienna, A-1060 Vienna
> Phone: +43-158801165300
> Email: peter.bl...@tuwien.ac.at
> WWW:   http://www.imc.tuwien.ac.at  WIEN2k: http://www.wien2k.at
> -
>
>
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Re: [Wien] Confirming Chern z2 topological invariants using BerryPhase

[Rubel, Oleg]

Dear Burhan,

Thank you for trying wcc.py.

Fig. 4 in https://doi.org/10.48550/arXiv.2303.16306 plots evolution of Wannier 
charge centers (bands 61-78 gives that total of 18 WCCs) stored in wcc.csv file 
(the sample is shown and discussed on page 6 of the preprint paper). You can 
compare your result with our wcc.csv available from 
https://zenodo.org/record/7761199

Your table listed below gives the total phase (essentially a sum of those 18 
WCCs). Bi2Se3 is a centrosymmetric material and, thus, the total phase = 0. 
Therefore, this table is not useful here. But if you try a Chern insulator, the 
table should show a 2pi jump.

For the speed of light you need to search older posts in the mailing list. I 
found suggestions there.

I hope it will help
Oleg

> -Original Message-
> From: Wien  On Behalf Of
> Burhan Ahmed
> Sent: Wednesday, July 26, 2023 1:40 PM
> To: wien@zeus.theochem.tuwien.ac.at
> Subject: [Wien] Confirming Chern z2 topological invariants using BerryPhase
> 
>   Caution: External email.
> 
> 
> Dear experts, I want to reproduce the results for the confirmation of Chern
> and Z2 topological invariants as calculated in the manuscript “Software
> implementation for calculating Chern and ℤ2 topological invariants of
> crystalline solids with WIEN2k all-electron density functional package” by
> Gomez, et. al. https://doi.org/10.48550/arXiv.2303.16306 (DOI:
> 10.48550/arXiv.2303.16306).
> 
> 
> 
> For this I have tried with the tutorial by Rubel available in
> https://github.com/rubel75/BerryPI  When I run the wcc.py in my case
> directory (where I have done my PBE+SOC calculation)  I got the following
> results
> 
> Total Berry phase on each Wislon loop for bands 61-78:
> 
> --
> 
> i   kPhase wrap.Phase unwrap.
> 
> (rad)   (rad)
> 
> --
> 
> 1  [0.000, 0.000, ***] 56.549   0.000
> 
> 2  [0.000, 0.026, ***] 56.549  -0.000
> 
> 3  [0.000, 0.053, ***] 56.549  -0.000
> 
> 4  [0.000, 0.079, ***] 56.549   0.000
> 
> 5  [0.000, 0.105, ***] 56.549   0.000
> 
> 6  [0.000, 0.132, ***] 56.549  -0.000
> 
> 7  [0.000, 0.158, ***] 56.549  -0.000
> 
> 8  [0.000, 0.184, ***] 56.549  -0.000
> 
> 9  [0.000, 0.211, ***] 56.549   0.000
> 
> 10  [0.000, 0.237, ***] 56.549  -0.000
> 
> 11  [0.000, 0.263, ***] 56.549   0.000
> 
> 12  [0.000, 0.289, ***] 56.549  -0.000
> 
> 13  [0.000, 0.316, ***] 56.549  -0.000
> 
> 14  [0.000, 0.342, ***] 56.549  -0.000
> 
> 15  [0.000, 0.368, ***] 56.549  -0.000
> 
> 16  [0.000, 0.395, ***] 56.549  -0.000
> 
> 17  [0.000, 0.421, ***] 56.549  -0.000
> 
> 18  [0.000, 0.447, ***] 56.549   0.000
> 
> 19  [0.000, 0.474, ***] 56.549   0.000
> 
> 20  [0.000, 0.500, ***] 56.549   0.000
> 
> --
> 
> Here "***" refer to the direction of the Wilson loop.
> 
> 
> 
> Where the value of wrap. remains constant in my case. I don't know what the
> mistake I have done. Also in the manuscript by Gomez and Rubel there is a plot
> in Figure 4 (a,b,c,d). I want to know how to plot this graph (is it from .csv
> file?). Also they have performed a reduce SOC calculation by increasing the
> speed of light from 137 to 300. In which file/step we can change the value of
> c.
> 
> 
> 
> Dear experts if possible please upload a video tutorial my mentioning the 
> steps
> on how to confirm Chern and Z2 topological invariants by Berryphse. It will be
> a great help for the researchers.
> 
> 
> 
> 
> 
> 
> 
> Regards
> 
> Burhan Ahmed
> 
> Research Scholar, AUS
> 
> 

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[Wien] Confirming Chern z2 topological invariants using BerryPhase

[Burhan Ahmed]

Dear experts, I want to reproduce the results for the confirmation of Chern and Z2 topological invariants as calculated in the manuscript “Software implementation for calculating Chern and ℤ2 topological invariants of crystalline solids with WIEN2k all-electron density functional package” by Gomez, et. al. https://doi.org/10.48550/arXiv.2303.16306 (DOI: 10.48550/arXiv.2303.16306). For this I have tried with the tutorial by Rubel available in https://github.com/rubel75/BerryPI  When I run the wcc.py in my case directory (where I have done my PBE+SOC calculation)  I got the following results Total Berry phase on each Wislon loop for bands 61-78:-- i   k    Phase wrap.    Phase unwrap.    (rad)   (rad)-- 1  [0.000, 0.000, ***] 56.549   0.000 2  [0.000, 0.026, ***] 56.549  -0.000 3  [0.000, 0.053, ***] 56.549  -0.000 4  [0.000, 0.079, ***] 56.549   0.000 5  [0.000, 0.105, ***] 56.549   0.000 6  [0.000, 0.132, ***] 56.549  -0.000 7  [0.000, 0.158, ***] 56.549  -0.000 8  [0.000, 0.184, ***] 56.549  -0.000 9  [0.000, 0.211, ***] 56.549   0.00010  [0.000, 0.237, ***] 56.549  -0.00011  [0.000, 0.263, ***] 56.549   0.00012  [0.000, 0.289, ***] 56.549  -0.00013  [0.000, 0.316, ***] 56.549  -0.00014  [0.000, 0.342, ***] 56.549  -0.00015  [0.000, 0.368, ***] 56.549  -0.00016  [0.000, 0.395, ***] 56.549  -0.00017  [0.000, 0.421, ***] 56.549  -0.00018  [0.000, 0.447, ***] 56.549   0.00019  [0.000, 0.474, ***] 56.549   0.00020  [0.000, 0.500, ***] 56.549   0.000--Here "***" refer to the direction of the Wilson loop. Where the value of wrap. remains constant in my case. I don't know what the mistake I have done. Also in the manuscript by Gomez and Rubel there is a plot in Figure 4 (a,b,c,d). I want to know how to plot this graph (is it from .csv file?). Also they have performed a reduce SOC calculation by increasing the speed of light from 137 to 300. In which file/step we can change the value of c.  Dear experts if possible please upload a video tutorial my mentioning the steps on how to confirm Chern and Z2 topological invariants by Berryphse. It will be a great help for the researchers.   RegardsBurhan AhmedResearch Scholar, AUS  ___
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Re: [Wien] calculation with lmbj potential

[Burhan Ahmed]

I check the possible ways of converging my system. The system converges with PBE+SOThe system converges with TB-mBJ+SO But The system doesn’t converges lmBJ+SOThe system doesn’t converges with PBE+nlvdwIt seems whenever I try to incorporate the van der waals interactions, the system becomes unstable. Karnel Type I choose is 1 and the rest default parameters are used.  I am still searching for the possible solution. Hoping for suggestions from the experts.   RegardsBurhan AhmedResearch Scholar, AUS  From: Laurence MarksSent: Monday, July 24, 2023 3:44 PMTo: A Mailing list for WIEN2k usersSubject: Re: [Wien] calculation with lmbj potential You should look at the BVS, i.e. "grep Bond *tnn" and compare it to what you have for bulk. You will see that you surface has bad values, so will be unstable. You need to do a lot more thinking and analysis (weeks) to find a chemically reasonable surface.---Professor Laurence Marks (Laurie)Department of Materials Science and EngineeringNorthwestern Universitywww.numis.northwestern.edu"Research is to see what everybody else has seen, and to think what nobody else has thought" Albert Szent-Györgyi On Mon, Jul 24, 2023, 05:28 Peter Blaha  wrote:Yes, R cells are first converted into H (making it already 3 times larger than the primitive R cell).The "accepting repeat atoms at z=0" makes the non-stoichiometry. It leads to 2 identical surfaces and inversion symmetry (cheaper calc), but non-stoiciometry.It is not always clear what the best model for a surface is. Yours is Te terminated, but maybe another termination is more favorable (Bi, or maybe another Te-layer ?)Am 24.07.2023 um 10:51 schrieb Burhan Ahmed:> The 6ql slab is created with 1x1x2 supercell with vacuum in Z direction > and accepting repeat atoms at z=0 (using x supercell program). At first > the x supercell convert rhombohedral cell into hexagonal and then from > hexagonal cell I have created the 1x1x2 supercell and then I took the > structure suggested by sgroup.> > Yes sorry for that I have used MSR1a method for the relaxation.> > The force convergence is set to 1 Ry.> > On Mon, 24 Jul, 2023, 2:06 pm Peter Blaha,  peter.bl...@tuwien.ac.at>> wrote:> >     I'm not sure how you get a non-stoichimetric cell with a multiplicative>     number of unit cells, unless you said you want to repeat the atom at>     z=0.>     Of course, without this extra layer, you may not have inversion and get>     2 different surface terminations in one calculation. This is the usual>     problem of slabs.>     Also symmetry will be reduced and "multiplicity" errors occur. But>     both,>     nn and sgroup create new struct files where this has been corrected.> >     If possible, I would also go to a smaller number of layers.> > >     Am 24.07.2023 um 10:13 schrieb Burhan Ahmed:>      > That is very true. I made the slab using the tutorial available>     in the>      > wien2k user manual by executing x-supercell program. What I found is>      > that the 6ql supercell consist of an extra Te atom. But whenever>     I try>      > to remove this atom I got multiplicity error. Sir, what is best>     possible>      > way of making slab with vacuum or surfaces??>      >>      > Thanks>      >>      > Regards>      >>      > Burhan Ahmed>      >>      > *Research Scholar, AUS *>      >>      > *From: *Laurence Marks laurence.ma...@gmail.com>     laurence.ma...@gmail.com>>>      > *Sent: *Saturday, July 22, 2023 6:30 PM>      > *To: *A Mailing list for WIEN2k users>      > wien@zeus.theochem.tuwien.ac.at>     wien@zeus.theochem.tuwien.ac.at>>>      > *Subject: *Re: [Wien] calculation with lmbj potential>      >>      > Others will probably give you suggestions about converging mBJ. Some>      > deeper comments.>      >>      > The most common reason that calculations behave badly is user error.>      > Sometimes this is doing the initialization wrong, often it is>     creating>      > an inappropriate model. Just because one can use x supercell or>     related>      > codes to create atomic positions does /not/ make them sensible.>      >>      > Your slab has a composition Bi12 Te19, i.e. it is Te rich. You>     therefore>      > have a reduced, n-type semiconductor with a small gap (about 0.1eV)>      > which will behave badly. If you look at your BVS you will see>     that atom>      > Te7 is severely underco-ordinated (unstable).>      >>      > I doubt that your slab will ever converge to anything which>     should be>      > published. Surfaces are not simple, it is unfortunately too easy>     to set>      > something up and get it wrong. (There are many papers in the>     literature>      > of dubious merit.)>      >>      > On Fri, Jul 21, 2023 at 10:47 PM Burhan Ahmed>     >      > burhan.ah...@aus.ac.in burhan.ah...@aus.ac.in     wrote:>      >>      >     Dear experts, I am doing an scf calculation taking lmbj>     potential.>      >