diff --git a/Modules/Ensemble.py b/Modules/Ensemble.py
index 36d01504f..2aea06791 100644
--- a/Modules/Ensemble.py
+++ b/Modules/Ensemble.py
@@ -1439,7 +1439,7 @@ class is created.
 
     #     # Get the symmetries from spglib
     #     super_structure = self.current_dyn.structure.generate_supercell(self.supercell)
-    #     spglib_syms = spglib.get_symmetry(super_structure.get_ase_atoms())
+    #     spglib_syms = spglib.get_symmetry(super_structure.get_spglib_cell())
 
     #     # Convert them into the cellconstructor format
     #     cc_syms = CC.symmetries.GetSymmetriesFromSPGLIB(spglib_syms, False)
@@ -1534,7 +1534,7 @@ def _unwrap_symmetries_(self):
 
         # Get the symmetries from spglib
         super_structure = self.current_dyn.structure.generate_supercell(self.supercell)
-        spglib_syms = spglib.get_symmetry(super_structure.get_ase_atoms())
+        spglib_syms = spglib.get_symmetry(super_structure.get_spglib_cell())
 
         # Convert them into the cellconstructor format
         cc_syms = CC.symmetries.GetSymmetriesFromSPGLIB(spglib_syms, False)
@@ -3655,6 +3655,15 @@ def get_free_energy_hessian(self, include_v4 = False, get_full_hessian = True, v
         # """
         #         raise NotImplementedError(ERROR_MSG)
 
+        # Check if the ensemble has been initialized
+        if len(self.forces) == 0:
+            n_forces = len(self.forces)
+            raise ValueError(
+                    f"Cannot evaluate free-energy Hessian: 'self.forces' is empty (len={n_forces}). "
+                    "Initialize or load the ensemble and compute energies and forces first."
+                )
+
+
         # Convert anything into the Ha units
         # This is needed for the Fortran subroutines
         self.convert_units(UNITS_HARTREE)
diff --git a/Modules/SchaMinimizer.py b/Modules/SchaMinimizer.py
index 976981687..c837d5f24 100644
--- a/Modules/SchaMinimizer.py
+++ b/Modules/SchaMinimizer.py
@@ -948,7 +948,7 @@ def print_info(self):
         print (" use spglib = ", self.use_spglib)
         if self.use_spglib:
             import spglib
-            print (" Symmetry group = {}".format(spglib.get_spacegroup(self.dyn.structure.get_ase_atoms())))
+            print (" Symmetry group = {}".format(spglib.get_spacegroup(self.dyn.structure.get_spglib_cell())))
         print (" Number of symmetries in the unit cell = ", self.N_symmetries)
 
         print ()
@@ -1097,7 +1097,7 @@ def init(self, verbosity = False, delete_previous_data = True, init_timer = True
 
                 import spglib
                 if verbosity:
-                    print("Symmetry group: ", spglib.get_spacegroup(self.dyn.structure.get_ase_atoms()))
+                    print("Symmetry group: ", spglib.get_spacegroup(self.dyn.structure.get_spglib_cell()))
 
                 self.N_symmetries = qe_sym.QE_nsym
 
@@ -1337,7 +1337,7 @@ def run(self, verbose = 1, custom_function_pre = None, custom_function_post = No
                 print ("")
                 print("Number of symmetries before the step: ", self.N_symmetries)
                 if self.use_spglib:
-                    print("Group space: ", spglib.get_spacegroup(self.dyn.structure.get_ase_atoms()))
+                    print("Group space: ", spglib.get_spacegroup(self.dyn.structure.get_spglib_cell()))
                 print ("Harmonic contribution to free energy = %16.8f meV" % (harm_fe * __RyTomev__))
                 print ("Anharmonic contribution to free energy = %16.8f +- %16.8f meV" % (anharm_fe * __RyTomev__,
                                                                                          np.real(err) * __RyTomev__))
diff --git a/Tutorials/LaH10/VariableCellRelaxation.ipynb b/Tutorials/LaH10/VariableCellRelaxation.ipynb
index 1f5db69d3..7f84f070b 100644
--- a/Tutorials/LaH10/VariableCellRelaxation.ipynb
+++ b/Tutorials/LaH10/VariableCellRelaxation.ipynb
@@ -222,7 +222,7 @@
    ],
    "source": [
     "import spglib\n",
-    "print (\"The original spacegroup is:\", spglib.get_spacegroup(dyn.structure.get_ase_atoms(), 0.05))"
+    "print (\"The original spacegroup is:\", spglib.get_spacegroup(dyn.structure.get_spglib_cell(), 0.05))"
    ]
   },
   {
@@ -244,7 +244,7 @@
     "# we define a function that prints the space group during the optimization\n",
     "space_groups = []\n",
     "def print_spacegroup(minim):\n",
-    "    spgroup = spglib.get_spacegroup(minim.dyn.structure.get_ase_atoms(), 0.05)\n",
+    "    spgroup = spglib.get_spacegroup(minim.dyn.structure.get_spglib_cell(), 0.05)\n",
     "    space_groups.append(spgroup)\n",
     "    \n",
     "    # We can save them in the output at each minimization step\n",
@@ -370,7 +370,7 @@
     }
    ],
    "source": [
-    "spglib.get_spacegroup(relax.minim.dyn.structure.get_ase_atoms(), 0.05)"
+    "spglib.get_spacegroup(relax.minim.dyn.structure.get_spglib_cell(), 0.05)"
    ]
   },
   {
@@ -390,7 +390,7 @@
     }
    ],
    "source": [
-    "spglib.get_spacegroup(dyn.structure.get_ase_atoms(), 0.1)"
+    "spglib.get_spacegroup(dyn.structure.get_spglib_cell(), 0.1)"
    ]
   },
   {