Hi. I tried to modify the tutorial for spin orbit coupling by replacing the system with a honeycomb lattice. However, I got this error, which came from bands: "Hopping from site 0 to site 12 does not match the dimensions of onsite Hamiltonians of these sites."Part of the code is attached. sys[lat.shape(rectangle, (1, 1))] = 0 #next nearest sys[lat.neighbors()] = 1.04 #nearest #### Define the left lead. #### sym = kwant.TranslationalSymmetry((-1, 0)) #from the left sym.add_site_family(lat.sublattices[0], other_vectors=[(-1, 2)]) sym.add_site_family(lat.sublattices[1], other_vectors=[(-1, 2)]) lead = kwant.Builder(sym) def lead1_shape(pos): x, y = pos return 0 < y < 10 for j in range(W): lead[lat.shape(lead1_shape, (0,j))] = 4 * t * identitymat + e_z * sigma_z lead[lat.neighbors()] = 0 #lead[(lat(0, j) for j in range(W))] = 4 * t * sigma_0 + e_z * sigma_z #hoppings in x-direction #lead[kwant.builder.HoppingKind((1, 0), 1, 1)] = \ # -t * identitymat - 1j * alpha * sigma_y # hoppings in y-directions #lead[kwant.builder.HoppingKind((0, 1), 1, 1)] = \ # -t * identitymat + 1j * alpha * sigma_x sys.attach_lead(lead) sys.attach_lead(lead.reversed()) return sys,lead def plot_bandstructure(sys, momenta): bands = kwant.physics.Bands(sys) energies = [bands(k) for k in momenta] plt.figure() plt.plot(momenta, energies) plt.xlabel("momentum [(lattice constant)^-1]") plt.ylabel("energy [t]") plt.show() def main(): sys,lead = make_system() honeycomb = sys.finalized() kwant.plot(sys) momenta = [0.01* pi * i for i in range(200)] plot_bandstructure(honeycomb.leads[1], momenta) #leads because of the attribute of silicene # We should see non-monotonic conductance steps. #plot_conductance(sys, energies=[0.01 * i - 0.3 for i in range(100)]) if __name__ == '__main__': main() James