> Thank you. Then to calculate the velocity, should I just divide the
> probability current by the integral of |𝜓|2 over the unit cell?
You could do that, but this is already done in Kwant, and you can read
the velocities off from the modes object [1].
Best,
Anton
[1]: https://kwant-project.org/doc/1/reference/generated/kwant. physics.PropagatingModes# kwant.physics.PropagatingModes