Dear all, I have a code for the Mobius structure, using python scripts. However, I want to construct a structure by adding hexagonal lattices in a Mobius structure. How can I do this using Kwant. Thank you in advance. Best, Nuwan, MSU, Starkville P.S.: The python script for the mobius structure is as follows: import numpy as np import matplotlib.pyplot as plt import matplotlib.tri as mtri from mpl_toolkits.mplot3d import Axes3D fig = plt.figure(figsize=plt.figaspect(0.5)) u = np.linspace(0, 2.0 * np.pi, endpoint=True, num=50) v = np.linspace(-0.5, 0.5, endpoint=True, num=10) u, v = np.meshgrid(u, v) u, v = u.flatten(), v.flatten() x = (1 + 0.5 * v * np.cos(u / 2.0)) * np.cos(u) y = (1 + 0.5 * v * np.cos(u / 2.0)) * np.sin(u) z = 0.5 * v * np.sin(u / 2.0) tri = mtri.Triangulation(u, v) ax = fig.add_subplot(1, 2, 1, projection='3d') ax.plot_trisurf(x, y, z, triangles=tri.triangles) ax.set_zlim(-1, 1) plt.show()