@@ -454,6 +454,11 @@ cdef class _LocalOperator:

                              'Declare the number of orbitals using the '

                              '`norbs` keyword argument when constructing '

                              'the site families (lattices).')

+        # TODO: Update this when it becomes clear how ND systems will be

+        #       implemented.

+        if is_vectorized(syst) and is_infinite(syst):

+            raise TypeError('Vectorized infinite systems cannot yet be '

+                            'used with operators.')

         self.syst = syst

         self.onsite, self._onsite_param_names = _normalize_onsite(

@@ -633,3 +633,12 @@ def test_vectorization(A):

     with pytest.raises(kwant._common.UserCodeError) as excinfo:

         bad_operator(wf)

     assert "did you remember to vectorize" in str(excinfo.value).lower()

+

+    # Infinite vectorized systems are incompatible with operators for now.

+    visyst = kwant.Builder(kwant.TranslationalSymmetry((-1, 0)), vectorize=True)

+    visyst[(lat(0, j) for j in range(5))] = sigmaz

+    visyst[lat.neighbors()] = sigmax

+    vifsyst = visyst.finalized()

+

+    with pytest.raises(TypeError):

+        A(vifsyst, vectorized_onsite, where=[(lat(1, 0), lat(0, 0))])