diff --git a/pyscf/dft/rks.py b/pyscf/dft/rks.py
index 70f5fdea37..807e32a0f5 100644
--- a/pyscf/dft/rks.py
+++ b/pyscf/dft/rks.py
@@ -539,5 +539,4 @@ def to_gpu(self):
         obj = lib.to_gpu(hf.SCF.reset(self.view(RKS)))
         # Attributes only defined in gpu4pyscf.RKS
         obj.screen_tol = 1e-14
-        obj.disp = None
         return obj
diff --git a/pyscf/dft/uks.py b/pyscf/dft/uks.py
index 19491012a7..cf2f7d7486 100644
--- a/pyscf/dft/uks.py
+++ b/pyscf/dft/uks.py
@@ -203,5 +203,4 @@ def to_gpu(self):
         obj = lib.to_gpu(SCF.reset(self.view(UKS)))
         # Attributes only defined in gpu4pyscf.RKS
         obj.screen_tol = 1e-14
-        obj.disp = None
         return obj
diff --git a/pyscf/gto/mole.py b/pyscf/gto/mole.py
index 0b09a51bdf..e330758b3c 100644
--- a/pyscf/gto/mole.py
+++ b/pyscf/gto/mole.py
@@ -3700,7 +3700,7 @@ def __getattr__(self, key):
                      '_repr_mimebundle_'):
             # https://github.com/mewwts/addict/issues/26
             # https://github.com/jupyter/notebook/issues/2014
-            raise AttributeError
+            raise AttributeError(f'Mole object has no attribute {key}')
 
         # Import all available modules. Some methods are registered to other
         # classes/modules when importing modules in __all__.
@@ -3721,8 +3721,10 @@ def __getattr__(self, key):
                 if xc in dft.XC:
                     mf.xc = xc
                     key = 'TDDFT'
-        else:
+        elif 'CI' in key or 'CC' in key or 'CAS' in key or 'MP' in key:
             mf = scf.HF(self)
+        else:
+            raise AttributeError(f'Mole object has no attribute {key}')
 
         method = getattr(mf, key)
 
diff --git a/pyscf/pbc/gto/cell.py b/pyscf/pbc/gto/cell.py
index 33891fd6c7..813cabe258 100644
--- a/pyscf/pbc/gto/cell.py
+++ b/pyscf/pbc/gto/cell.py
@@ -971,7 +971,7 @@ def __getattr__(self, key):
                      '_repr_mimebundle_'):
             # https://github.com/mewwts/addict/issues/26
             # https://github.com/jupyter/notebook/issues/2014
-            raise AttributeError
+            raise AttributeError(f'Cell object has no attribute {key}')
 
         # Import all available modules. Some methods are registered to other
         # classes/modules when importing modules in __all__.
@@ -994,8 +994,10 @@ def __getattr__(self, key):
                     if xc in XC:
                         mf.xc = xc
                         key = 'KTDDFT'
-            else:
+            elif 'CI' in key or 'CC' in key or 'MP' in key:
                 mf = scf.KHF(self)
+            else:
+                raise AttributeError(f'Cell object has no attribute {key}')
             # Remove prefix 'K' because methods are registered without the leading 'K'
             key = key[1:]
         else:
@@ -1008,8 +1010,10 @@ def __getattr__(self, key):
                     if xc in XC:
                         mf.xc = xc
                         key = 'TDDFT'
-            else:
+            elif 'CI' in key or 'CC' in key or 'MP' in key:
                 mf = scf.HF(self)
+            else:
+                raise AttributeError(f'Cell object has no attribute {key}')
 
         method = getattr(mf, key)