Monatomic.closest doesn't check input dimensionality
To reproduce:
import kwant
template = kwant.continuum.discretize("k_x**2 + k_y**2")
syst = kwant.Builder()
syst.fill(template, (lambda site: site.tag[0]**2 + site.tag[1]**2 < 10), start=[0])
Adds a bunch of sites.
Expected result: ValueError
raised because the start has a mismatched dimensionality.
Actually even better:
import kwant, pytest
pytest.raises(ValuError, kwant.lattice.square().closest, [0])
Edited by Anton Akhmerov