diff --git a/gpu4pyscf/solvent/hessian/pcm.py b/gpu4pyscf/solvent/hessian/pcm.py
index 0af6ae81..587b7de0 100644
--- a/gpu4pyscf/solvent/hessian/pcm.py
+++ b/gpu4pyscf/solvent/hessian/pcm.py
@@ -280,6 +280,8 @@ def make_h1(self, mo_coeff, mo_occ, chkfile=None, atmlst=None, verbose=None):
                 h1aoa[i0] += dva[i0]
                 h1aob[i0] += dvb[i0]
             return h1aoa, h1aob
+        else:
+            raise NotImplementedError('Base object is not supported')
     def _finalize(self):
         # disable _finalize. It is called in grad_method.kernel method
         # where self.de was not yet initialized.
diff --git a/gpu4pyscf/solvent/hessian/smd.py b/gpu4pyscf/solvent/hessian/smd.py
index ecee95dd..cbeef82e 100644
--- a/gpu4pyscf/solvent/hessian/smd.py
+++ b/gpu4pyscf/solvent/hessian/smd.py
@@ -307,7 +307,8 @@ def make_h1(self, mo_coeff, mo_occ, chkfile=None, atmlst=None, verbose=None):
                 h1aoa[i0] += dva[i0]
                 h1aob[i0] += dvb[i0]
             return h1aoa, h1aob
-
+        else:
+            raise NotImplementedError('Base object is not supported')
     def _finalize(self):
         # disable _finalize. It is called in grad_method.kernel method
         # where self.de was not yet initialized.