relax sanity_check wavefunction for alkaline atoms

Author: johannes-moegerle

src/ryd_numerov/radial/wavefunction.py

@@ -283,6 +283,10 @@ def sanity_check(self, z_stop: float, run_backward: bool) -> bool:  # noqa: C901
         elif n <= 16:
             tol = 2e-3
 
+        species = self.radial_state.species
+        if species.number_valence_electrons == 2:
+            tol = 2e-2
+
         if inner_weight_scaled_to_whole_grid > tol:
             warning_msgs.append(
                 f"The wavefunction is not close to zero at the inner boundary"