diff --git a/simple_nn/features/symmetry_function/__init__.py b/simple_nn/features/symmetry_function/__init__.py
index 28aa7c1..17faabf 100644
--- a/simple_nn/features/symmetry_function/__init__.py
+++ b/simple_nn/features/symmetry_function/__init__.py
@@ -36,7 +36,7 @@ def __init__(self, inputs=None):
         self.default_inputs = {'symmetry_function': 
                                   {
                                       'params': dict(),
-                                      'refdata_format':'vasp_out',
+                                      'refdata_format':'vasp-out',
                                       'compress_outcar':True,
                                       'data_per_tfrecord': 150,
                                       'valid_rate': 0.1,