<html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>Dear Kenan,</div>
<div> </div>
<div>It seems you may be confusing the "num_wann" and "num_bands" inputs. From the manual: </div>
<div> </div>
<div>- "num_bands" is "Number of bands passed to the code"</div>
<div>- "num_wann" is "Number of WF"</div>
<div> </div>
<div>In other words, "num_bands" are the bands <em>before</em> disentanglement, and "num_wann" the number <em>after</em> disentanglement. Importantly, the number of bands that need to lie within the energy window is "num_wann", not "num_bands".</div>
<div> </div>
<div>The way I understand the error message is this: Of the 96 bands that <em>are</em> passed to the code, there are fewer than "num_wann" inside the given energy window. Increasing "num_bands" can fix this because more bands are passed to Wannier90 to begin with. As an extreme example, if "num_wann" > "num_bands", the calculation will never work regardless of energy windows.</div>
<div> </div>
<div>In general, "num_bands" should be the same as the number of bands produced by the first-principles code, minus the number of "exclude_bands". I'm not sure exactly what happens when this is not the case, but maybe it is silently ignored in your case. </div>
<div>
<div> </div>
<div>Best regards,</div>
<div>Dominik</div>
<div> </div>
<div>---</div>
<div>Dominik Gresch</div>
<div>Simulation Engineer</div>
<div>Microsoft Quantum</div>
<div> </div>
<div>
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<div name="quoted-content"><br/>
<br/>
Date: Thu, 1 Apr 2021 17:58:37 +0300<br/>
From: Kenan Song <kenan.song@kaust.edu.sa><br/>
To: hoangminh nguyenduy <nguyenduyhoangminh@gmail.com><br/>
Cc: "wannier@lists.quantum-espresso.org"<br/>
<wannier@lists.quantum-espresso.org><br/>
Subject: Re: [Wannier] Enquiry about the Failure in Wannierization<br/>
Calculation<br/>
Message-ID:<br/>
<CAMbJXZ9w6u-bcg7B5YkymnwTYUL8tive=xHYpZurj=C9aD6PYA@mail.gmail.com><br/>
Content-Type: text/plain; charset="utf-8"<br/>
<br/>
Dear Hoangminh,<br/>
<br/>
Thank you for the suggestion.<br/>
<br/>
I will check that and change the energy window value, as you suggest.<br/>
<br/>
On the other hand, I really do not understand why this problem happened. I<br/>
did the wannierization two times. First time, I set num_bands = 112 and<br/>
dis_win_max = 150.0; then, the calculation could be done successfully. I<br/>
think that this means that 150 eV includes more bands than 112 bands;<br/>
otherwise, the calculation would report the error message (dis_windows:<br/>
Energy window contains fewer states than number of target WFs).<br/>
<br/>
Second time, I only changed num_bands parameter to 96 and other parameters<br/>
remained the same. I suppose that 150 eV should also include far more bands<br/>
than 96 bands. Would you please provide me some possible reasons why the<br/>
calculation failed, saying 'dis_windows: Energy window contains fewer<br/>
states than number of target WFs'?<br/>
<br/>
Thank you very much again.<br/>
<br/>
Kind regards,<br/>
<br/>
Kenan Song<br/>
Post Doctor in KAUST<br/>
<br/>
On Thu, Apr 1, 2021 at 5:06 PM hoangminh nguyenduy <<br/>
nguyenduyhoangminh@gmail.com> wrote:<br/>
<br/>
> Dear Kenan,<br/>
><br/>
><br/>
><br/>
> Although 150 >> 15, would you mind checking whether the highest level when<br/>
> num_bands=96 is still higher than the dis_froz_max value?<br/>
><br/>
> If the value of dis_froz_max is fine, may you try decreasing the value of<br/>
> dis_win_max so that it is just above the 96th band?<br/>
><br/>
><br/>
><br/>
> Best,<br/>
><br/>
> Minh.<br/>
><br/>
> *From: *Kenan Song <kenan.song@kaust.edu.sa><br/>
> *Sent: *Thursday, April 1, 2021 6:03 PM<br/>
> *To: *Stepan Tsirkin <tsirkinss@gmail.com><br/>
> *Cc: *wannier@lists.quantum-espresso.org<br/>
> *Subject: *Re: [Wannier] Enquiry about the Failure in Wannierization<br/>
> Calculation<br/>
><br/>
><br/>
><br/>
> Dear Stepan,<br/>
><br/>
><br/>
><br/>
> Thank you for the suggestion.<br/>
><br/>
><br/>
><br/>
> I used the same VASP code (version 5.4.4) to do the calculation for these<br/>
> two calculations. The only difference is that I set NBANDS flag as 112 and<br/>
> 96 respectively in order to interface with WANNIER90 code but I found that<br/>
> the first wannierization with num_bands=112 could be done successfully;<br/>
> while the second one with num_bands=96 failed. All other parameters in the<br/>
> wannierization step are the same.<br/>
><br/>
><br/>
><br/>
> In the DFT self-consistent calculation, the fermi energy level is located<br/>
> at 8.51 eV and the WANNIER90 code took this value as the Fermi level in its<br/>
> calculations. The minimum eigen value/band is located at -55 eV but they<br/>
> are just 6 highly localised bands (straight lines) and I am interested in<br/>
> bands close to Fermi energy level. This is why I choose dis_win_min as -0.5<br/>
> eV.<br/>
><br/>
><br/>
><br/>
> I could use larger values (160 ~ 200) for num_bands flag but I am afraid<br/>
> that the dis_win_max flag needs to be set up as an even higher value. I am<br/>
> not sure whether the same error message (dis_windows: Energy window<br/>
> contains fewer states than number of target WFs) would pop up.<br/>
><br/>
><br/>
><br/>
> Would you please give me some more suggestions/comments? Thank you so much<br/>
> for your help.<br/>
><br/>
><br/>
><br/>
> Kind regards,<br/>
><br/>
><br/>
><br/>
> Kenan Song<br/>
><br/>
> Post Doctor in KAUST<br/>
><br/>
><br/>
><br/>
> On Thu, Apr 1, 2021 at 12:06 PM Stepan Tsirkin <tsirkinss@gmail.com><br/>
> wrote:<br/>
><br/>
> Dear Kenan,<br/>
><br/>
> do you meant that hte first (successful) calculation was done with another<br/>
> code (not VASP) ?<br/>
><br/>
> Different codes may produce bandstructures shifted, also depending on<br/>
> pseudopotential there might be a different number of semi-core electrons<br/>
> included. Are you sure all your bands are above the dis_win_min = -0.5<br/>
><br/>
> If you remove dis_win_min and dis_win_max - then all bands will be<br/>
> included.<br/>
><br/>
> However, for a good disentanglement, typically a much larger number of<br/>
> bands should be included, then the number of Wannier functions. I would<br/>
> use at least a double, i.e. num_bands~= 160-200.<br/>
><br/>
> Regards,<br/>
><br/>
> Stepan Tsirkin,<br/>
> University of Zurich.<br/>
> <a href="http://wannier-berri.org" target="_blank">http://wannier-berri.org</a><br/>
> <<a href="https://urldefense.com/v3/__http:/wannier-berri.org__;!!Nmw4Hv0!mcRhIZFtkkQwIAT8TyKbCdjzSk8IetfWcmjwpRZp-udWAbKcLoQ1Q9Vamt-4HoG-iizG$" target="_blank">https://urldefense.com/v3/__http:/wannier-berri.org__;!!Nmw4Hv0!mcRhIZFtkkQwIAT8TyKbCdjzSk8IetfWcmjwpRZp-udWAbKcLoQ1Q9Vamt-4HoG-iizG$</a>><br/>
><br/>
> On 01.04.21 10:49, Kenan Song wrote:<br/>
><br/>
> Dear All,<br/>
><br/>
><br/>
><br/>
> Can I ask a question?<br/>
><br/>
><br/>
><br/>
> I am running the wannierization now and it could be done successfully with<br/>
> the following parameter settings in the wannier90.win file.<br/>
><br/>
><br/>
><br/>
> num_wann = 80<br/>
><br/>
> num_bands = 112<br/>
><br/>
><br/>
><br/>
> num_iter = 50<br/>
><br/>
> guiding_centres = .true.<br/>
><br/>
> dis_num_iter = 1000<br/>
><br/>
><br/>
><br/>
> dis_froz_min = -0.5<br/>
><br/>
> dis_froz_max = 15.0<br/>
><br/>
> dis_win_min = -0.5<br/>
><br/>
> dis_win_max = 150.0<br/>
><br/>
><br/>
><br/>
> spinors = .true.<br/>
><br/>
> begin projections<br/>
><br/>
> Ni : s; p; d<br/>
><br/>
> N : s; p<br/>
><br/>
> Mn : s; p; d<br/>
><br/>
> end projections<br/>
><br/>
><br/>
><br/>
> begin unit_cell_cart<br/>
><br/>
> 3.8784000000 0.0000000000 0.0000000000<br/>
><br/>
> 0.0000000000 3.8784000000 0.0000000000<br/>
><br/>
> 0.0000000000 0.0000000000 3.8784000000<br/>
><br/>
> end unit_cell_cart<br/>
><br/>
><br/>
><br/>
> begin atoms_cart<br/>
><br/>
> Ni 0.000000000 0.000000000 0.000000000<br/>
><br/>
> N 0.500000000 0.500000000 0.500000000<br/>
><br/>
> Mn 0.000000000 0.500000000 0.500000000<br/>
><br/>
> Mn 0.500000000 0.000000000 0.500000000<br/>
><br/>
> Mn 0.500000000 0.500000000 0.000000000<br/>
><br/>
> end atoms_cart<br/>
><br/>
><br/>
><br/>
> write_hr = .true.<br/>
><br/>
> bands_plot = .true.<br/>
><br/>
> bands_num_points = 100<br/>
><br/>
> begin kpoint_path<br/>
><br/>
> Gamma 0.0 0.0 0.0 X 0.0 0.5 0.0<br/>
><br/>
> X 0.0 0.5 0.0 M 0.5 0.5 0.0<br/>
><br/>
> M 0.5 0.5 0.0 R 0.5 0.5 0.5<br/>
><br/>
> R 0.5 0.5 0.5 Gamma 0.0 0.0 0.0<br/>
><br/>
> Gamma 0.0 0.0 0.0 M 0.5 0.5 0.0<br/>
><br/>
> M 0.5 0.5 0.0 R 0.5 0.5 0.5<br/>
><br/>
> R 0.5 0.5 0.5 X 0.0 0.5 0.0<br/>
><br/>
> end kpoint_path<br/>
><br/>
> bands_plot_format = gnuplot<br/>
><br/>
><br/>
><br/>
> mp_grid = 21 21 21<br/>
><br/>
><br/>
><br/>
> begin kpoints<br/>
><br/>
> 0.000000000000 0.000000000000 0.000000000000<br/>
><br/>
> 0.047619047619 0.000000000000 0.000000000000<br/>
><br/>
> 0.095238095238 0.000000000000 0.000000000000<br/>
><br/>
> ...<br/>
><br/>
> -0.476190476190 0.476190476190 -0.476190476190<br/>
><br/>
> 0.476190476190 0.476190476190 -0.476190476190<br/>
><br/>
> -0.476190476190 -0.476190476190 0.476190476190<br/>
><br/>
> end kpoints<br/>
><br/>
><br/>
><br/>
> Then, I re-did the DFT calculation with VASP and set NBANDS to 96 to<br/>
> interface with WANNIER90. In the wannierizaion step, I only changed<br/>
> num_bands flag from 112 to 96 and kept all other parameter settings the<br/>
> same; however, the calculation failed. The wannier90.wout file has the<br/>
> following information at the end.<br/>
><br/>
><br/>
><br/>
> Error at k-point 1 ndimwin 76 num_wann 80<br/>
><br/>
> Exiting.......<br/>
><br/>
> dis_windows: Energy window contains fewer states than number of target WFs<br/>
><br/>
><br/>
><br/>
> I do not understand why it is that. I suppose that if the num_bands flag<br/>
> with 112 in the previous calculation could be done successfully;<br/>
> then, num_bands flag with 96 in this new calculation should be done<br/>
> successfully as well because the dis_win_max flag in these two calculations<br/>
> always remained 150.0.<br/>
><br/>
><br/>
><br/>
> Would anyone please give me some suggestions/comment on this issue? Thank<br/>
> you very much.<br/>
><br/>
><br/>
><br/>
> Kind regards,<br/>
><br/>
><br/>
><br/>
> Kenan Song<br/>
><br/>
> Post Doctor in KAUST<br/>
><br/>
><br/>
></div>
</div>
</div>
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