Py4vasp Plots

[alexander_duong]

Hello,

Is there a way using py4vasp to change the y-axis (energy) limits when plotting the band structure and exporting it to a file? I know that I can zoom in to the range I want to look at, but is there a way so that it only outputs a plot within that range?

Thanks!

[andreas.singraber]

Hello!

Sorry for the late reply!
To change the y-axis limits you can try the following:

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fig = calc.band.to_plotly()

This will take the band structure data and convert it into a plotly figure given the name fig. Then you can use plotly commands to modify the looks of the graph, e.g., in your case

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fig.update_layout(yaxis_range=[-4,4])

If you save the image with

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fig.write_image("bands.png")

the y-axis should be within the given limits also in the file output.

If you prefer to extract the band structure data directly and create your own graph then use the to_dict() method:

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data = calc.band.to_dict()
print(data.keys())
print(data["bands"])

returns:

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dict_keys(['kpoint_distances', 'kpoint_labels', 'fermi_energy', 'bands', 'occupations', 'projections'])
[[-12.37398323  -0.13705124  -0.13698808  -0.13698805   2.71211925
    2.71230009   2.7123001    3.59369258   8.12772068   8.12772071
    8.3210912   11.76821744  11.76826679  11.76826679  15.79650954
   24.22109415]
 [-12.16506281  -1.73013217  -0.42311383  -0.42301317   2.66585147
    3.1402435    3.14033932   4.92773258   7.62707016   7.62710245
    9.11779172  11.16938987  12.97571267  12.97575359  17.09479657
   22.02225903]
...

Hope this works for you!

All the best,
Andreas Singraber

[alexander_duong]

Thank you for your help!

[hongyang_ma]

Hi Andreas,

I'm curious about how to project the x2-y2 orbital using py4vasp. Could you please let me know the name used in py4vasp for the x2-y2 orbital?

Regards,
Hongyang

[andreas.singraber]

Hello Hongyang,

as far as I know the labels should be identical to the short ones found in the PROCAR file. There is only one exception: the hyphen in x2-y2 would conflict with the selection syntax in py4vasp and hence is renamed dx2y2. Here is the full list:

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s
py, pz, px
dxy, dyz, dz2, dxz, dx2y2,
fy3x2, fxyz, fyz2, fz3, fxz2, fzx2, fx3 

Unfortunately, I cannot find this small change anywhere in the documentation... sorry for this inconvenience, I will suggest this to my colleagues.

All the best,
Andreas Singraber

[hongyang_ma]

Dear Andreas,

Exactly! I've noticed that all the orbital labels work except for dx2-y2. It would be helpful to have an update in the document. Thank you very much!

Regards,
Hongyang

[andreas.singraber]

Hello!

Just another useful remark: you can get the list of all projections available in your data via

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calc.projector.selections()

which will return a dictionary where you can find dx2y2 in the orbital entry.

Best,
Andreas Singraber

[hongyang_ma]

Thanks, Andreas!

Regards,
Hongyang