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[phibeck]

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[Chen-Ziyan]

Hello, FermiSee is very easy to use, especially the feature for plotting Fermi surfaces, which is exactly what I need. However, I've encountered two issues during usage:

Firstly, it seems that the Fermi surface functionality only correctly plots the Fermi surface within the kz=0 plane. When I adjust the coordinates of high-symmetry points, the graphics change, but I cannot determine which plane's Fermi surface is being plotted.

The second issue relates to file uploads. Is there a size limit for uploading w90_hr files in FermiSee? The example provided with the svo_hr file and my own hr file, which is 1.2MB in size, work well and correctly plot the band structure. However, when I try to upload a file of approximately 2.4MB, it consistently fails.

[the-hampel]

Hi @Chen-Ziyan ,

Thank you for reporting the issue with the Fermi surface cuts. Indeed, there seems to be a mixture of bug / missing functionality when it comes to moving along kz. We will try to fix this in the couple of days! I will create an issue from this threat. Please continue discussing there.

For your other question regarding file size. There is some file size limit on the web server where FermiSee is hosted. Do you have the possibility to use FermiSee as docker image on your local system? You can clone the unstable branch of this repo and if you have docker installed you can just run docker-compose up in the git directory. This will build the FermiSee docker image and start it. You can then go in your browser to http://127.0.0.1:9375 to access it. Check if the same error exists there.

Best,
Alex

[Chen-Ziyan]

Thank you for your suggestions. After downloading and running locally, I encountered the issues. In tab1_callbacks.py at line 252, the code:
orb_options = [{'label': str(k), 'value': str(k)} for i, k in enumerate(list(permutations([i for i in range(tb_data['n_wf'])])))]
was intended to provide users with all possible orbital sequences, which is a thoughtful feature. However, for my 2.48Mb file containing 12 orbitals, generating all permutations of 12 orbitals consumes significant time, leading to the delay I previously experienced in file reading.

I've identified the reason for the incorrect Fermi surface slicing. In tab2_callbacks.py, line 53 fixes kz to 0, causing the line in TB_functions.py at line 106:
path_FS = [(Y/(N_kxy-1)kyi +kzZ, X+Y/(N_kxy-1)kyi+kzZ)]
to fail to move correctly along the z-axis. One solution I propose is to fix kz=1 and allow users to input the value of Z in the get_kx_ky_FS function, enabling slicing along the z-axis for any Fermi surface.

[the-hampel]

Hi @Chen-Ziyan ,
can we continue discussing in the opened issue? Thanks! #4 I replied to you there.