diff --git a/qef/models/utils.py b/qef/models/utils.py
new file mode 100644
index 0000000..2f29cbd
--- /dev/null
+++ b/qef/models/utils.py
@@ -0,0 +1,19 @@
+import multiprocessing
+from tqdm import tqdm
+
+def parallel(propertyClass, filesname):
+    """parallelize calls to an external executable
+
+            Parameters
+            ----------
+            propertyClass: X-ray property class
+
+            filesname: :pdb_file
+
+            Returns
+            -------
+            profiles: : list of properties profiles
+
+        """
+    with multiprocessing.Pool(processes=multiprocessing.cpu_count()) as pool:
+        profiles = list(tqdm(pool.imap(propertyClass().from_crysol_pdb, filesname),total=len(filesname)))