Hello, I have just started using kwant, and I am trying to write a code excerpt that saves a figure of my system, but I just get a blank 3-D space. The code is the following, as taken by the TBModels website: ----------------------------------------------------------------- import kwant import tbmodels import wraparound import numpy as np import scipy.linalg as la import matplotlib matplotlib.use('agg') import matplotlib.pyplot as plt model = tbmodels.Model.from_wannier_files( hr_file='..._hr.dat', wsvec_file='..._wsvec.dat', xyz_file='..._centres.xyz', win_file='....win' ) lattice = model.to_kwant_lattice() wire = kwant.Builder() def shape(p): x, y, z = p return -20 < x < 20 and -5 < y < 5 and -5 < z < 5 wire[lattice.shape(shape, (0, 0, 0))] = 0 model.add_hoppings_kwant(wire) fig = plt.figure() ax = plt.subplot() ax = kwant.plot(wire) plt.savefig('wire.png') ---------------------------------------------------------------------------------------- If anyone knows whether the problem is with the system or with the plotting it would be greatly appreciated. Regards -- Dr. Eleni Chatzikyriakou Computational Physics lab Aristotle University of Thessaloniki elchatz@auth.gr - tel:+30 2310 998109