Hi Dears, why can tags assume only integers values? For example: lat = kwant.lattice.Polyatomic([(1, 0, 0), (0, 1, 0),(0, 0, 1)], [(1, 0, 0), (0.0, 1, 0.0),(0.0, 0.0, 1)],norbs=1) syst = kwant.Builder() # it is possible: syst[a(1,0,0)]=4 and syst[a(1.5,0,0)]=4 gives me the same result as before? Both of them says:

...

...

a(1,0,0)

Site(kwant.lattice.Monatomic([[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]], [0.0, 0.0, 0.0], '0', 1), array([1, 0, 0]))

...

...

a(1.5,0,0)

Site(kwant.lattice.Monatomic([[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]], [0.0, 0.0, 0.0], '0', 1), array([1, 0, 0])) The later should be: Site(kwant.lattice.Monatomic([[1.0, 0.0, 0.0], [0.0, 1.0, 0.0], [0.0, 0.0, 1.0]], [0.0, 0.0, 0.0], '0', 1), array([1.5, 0, 0])) best regards. Eudes.