No way to plot bands written by save_bands

[Technici4n]

I am trying to save bands to a jld2 file with save_bands, however if I do that I can't seem to easily load them for plotting with DFTK later? 😄

[mfherbst]

Yeah that's currently not possible. Feel free to suggest something. May involve finally changing from named tuples to something else for holding scf results and bands.

[Technici4n]

The biggest problem seems to be that the basis is not saved. I'm sure we can continue without a dedicated struct for a while if we want to. 😄

[niklasschmitz]

I also ran into this today. A load_bands being a stripped down version of load_scfres sounds useful. The basis can be reconstructed from the current format with load_basis from the JLD2Ext. What currently seems to work:

band_data = compute_bands(scfres)
save_bands("bands.jld2", band_data)
jld = jldopen("bands.jld2")
basis = Base.get_extension(DFTK, :DFTKJLD2Ext).load_basis(jld) 

[mfherbst]

We can certainly hack something, but in principle I dont see why plotting the bands needs a basis if the bands eigenvalues are already computed.