The tight binding approximation is good for states with a wavelength considerably larger than than the lattice constant (a); equivalently (k*a<<1), where k is the wave number . In the tutorial "2.2.2. Transport through a quantum wire" of Kwant <https://kwant-project.org/doc/1.0/tutorial/tutorial1#transport-through-a-quantum-wire>, the energies, at which the conductance has been calculated, varies from 0 to 1 in units of t, where t=ћ^2/(2ma^2). Is it consistent with the validity of tight binding approximation, as it seems that would required the energy to be << 1 (in units of t)?
Regards, Monika
