I would like to either get the local Green's function at a single site of my system with the effect of the leads included. The Green's function method of Kwant does not give me this, right? But I could get I want combining the system Hamiltonian if the leads self- energy: Heff = Hsys + Sigma However, "sys.hamiltonian_submatrix()" gives me the full Hsys, while "sys.leads[0].selfenergy(energy=0.01)" gives me only the submatrix of lead interface. How can I reshape the self-energy to obtain the Heff? Once I have Heff, I can calculate the GF via Geff = [w - i.eta - Heff]^{-1} Then, how can I access the local GF of a given site? Geff[lat(i,j)]? Best, Gerson