def test_basic_plaquettes_distance(self):
lattice = HexagonalLattice([8, 8])
for site1, site2, site3, site4 in lattice.basic_plaquettes():
assert abs(sum(a * a for a in lattice.spatial_coordinates(site1 - site2.bs)) - 1) < .0000001
assert abs(sum(a * a for a in lattice.spatial_coordinates(site2 - site3.bs)) - 1) < .0000001
assert abs(sum(a * a for a in lattice.spatial_coordinates(site3 - site4.bs)) - 1) < .0000001
assert abs(sum(a * a for a in lattice.spatial_coordinates(site4 - site1.bs)) - 1) < .0000001
