docs: def load_mol(self, mol_file):
          """Loads a MOL file of the ligand (submitted by user) into RDKit environment.
              Takes:
                  * mol_file * - user submitted MOL file of the ligand
              Output:
                  * self.mol_mda * - the ligand as MDAnalysis Universe,
                  * self.mol * - the ligand in RDKit environment as Mol object.
          """
          #Check if MOL file has been provided correctly and can be loaded in MDAnalysis
          if mol_file is None:
              mol_file = "lig.mol"
  
          self.mol = Chem.MolFromMolFile(mol_file,removeHs=False,sanitize=False)
          try:
              self.mol.UpdatePropertyCache(strict=False)
          except AttributeError:
              assert self.mol != None, "The MOL file could not be imported in RDKit environment. Suggestion: Check the atomtypes."
          assert self.mol != None, "The MOL file could not be imported in RDKit environment."