If I understand your question correctly, I have done this by extracting a Hamiltonian from the wrapped system using hamiltonian_submatrix (with whatever wavevector you want as an argument) and finding the eigenvalues of that matrix. I’ve attached a jupyter notebook that uses kwant to calculate Si’s band structure along high-symmetry directions. In the notebook, cell 6 is the relevant one. That said, others may know a cleaner way to do this.
That said, what is your ultimate goal? If it’s simply to compute band structures of a bulk material, then you can just write down the matrix without kwant and find its eigenvalues. (I’ve attached a second notebook that does that.) I don’t think that kwant simplifies the process. If you want to later want to do some transport simulation, then starting with kwant could prove useful.
Dear kwant developers and users,
I want to calculate and plot the band structure of bulk 2D material along some high-symmetry lines in the Brillouin zone (e.g. Gamma-->K-->M--Gamma), i.e. the 1D band structure.
I found that someone already posted a relevant issue and some useful solutions were also given. For example, see https://kwant-discuss.kwant-project.narkive.com/2fT27IJh/kwant-for-bulk-system.
However, these solutions are only for calculating and plotting the full 2D band structure in the Brillouin zone.
Can anyone give some useful solutions to my concern? Your help is much appreciated.
Thank you and best regards,