Dear Mohit, Sorry, I wrote it without testing. Indeed, we need to provide the indices of the sites and not the sites themselves. Please change Sites1, and Sites2 in the hamiltonian_submatrix as follows
Sites1=[syst.id_by_site[lat(5, j)] for j in range(W)] I hope this helps. Adel On Thu, Jun 18, 2020 at 12:52 AM <mohit.gupta9...@gmail.com> wrote: > Dear Abbout, > Thank you for your helpful reply it clears up a lot. I tried to obtain H12 > as you mentioned: > H12=syst.hamiltonian_submatrix(to_sites=Sites1, from_sites=Sites2) > But it gives me the error that "an integer is required". > Although that is not a major issue I could try to construct H12 manually. > Thanks a lot for your help. > -- Abbout Adel