Changed the default of load_families_only (#704)

This solved issues #703 and circumventing issue #702 by loading all
reaction families by default.

arc/rmgdb.py

@@ -39,7 +39,7 @@ def make_rmg_database_object() -> RMGDatabase:
 
 
 def load_families_only(rmgdb: RMGDatabase,
-                       kinetics_families: Union[str, list] = 'default'):
+                       kinetics_families: Union[str, list] = 'all'):
     """
     A helper function for loading kinetic families from RMG's database.
 
@@ -380,3 +380,20 @@ def get_family(rmgdb: RMGDatabase,
             family.save_order = True
             return family
     return None
+
+
+def clean_rmg_database_object(db: RMGDatabase) -> RMGDatabase:
+    """
+    clears the global RMG database object.
+
+    Args:
+        db (RMGDatabase): the database object
+
+    Returns:
+        RMGDatabase: the database object
+    """
+    global rmg_database_instance
+    del rmg_database_instance
+    rmg_database_instance = None
+
+    return make_rmg_database_object()

arc/rmgdb_test.py

@@ -123,6 +123,13 @@ def test_get_family(self):
         self.assertEqual(family_4.label, 'intra_H_migration')  # returns the correct capitalization
         self.assertTrue(family_4.save_order)
 
+    def test_clean_rmg_database_object(self):
+        """Test the clean_rmg_database_object() function"""
+        self.rmgdb = rmgdb.clean_rmg_database_object(self.rmgdb)
+        self.assertIsNone(self.rmgdb.thermo)
+        self.assertIsNone(self.rmgdb.transport)
+        self.assertIsNone(self.rmgdb.kinetics)
+        rmgdb.load_rmg_database(rmgdb=self.rmgdb)
 
 if __name__ == '__main__':
     unittest.main(testRunner=unittest.TextTestRunner(verbosity=2))