Dear all, I am using kwant to calculate the transmission of a bulk system. I use " sys = kwant.wraparound.wraparound(sys) and lead = kwant.wraparound.wraparound(lead, keep=0)" to change my tight-binding ribbon system to a bulk system. The transmission is obtained using: kys = np.arange(-0.5, 0.5, 0.001) for ky in kys: smatrix = kwant.smatrix(sys, energy, [ky]) transmission.append(smatrix.transmission(1, 0)) I want to obtain the Transmission vs the incident angle of an electron, and I also need to do the integration ∫T(ky, E) dky or ∫T(θ,E)cosθdθ. I do not undstand the ky in the system with kwant.wraparoun, what is the unit of ky, what is k here for the system, how to obtain T(θ,E) .Can you give me some advices on this?Thanks in advance. The definition of incident angle is shown in the attached Fig.1， the band structure for my bulk system is shown in attached Fig.2 and the Tranmission vs ky is shown in Fig.3 (I do not know how to set the values for ky). Regards, Hosein Khani