diff --git a/parser/parser-asap/constraint_conversion.py b/parser/parser-asap/constraint_conversion.py
index a3591b390a45fe39789970cc9475cc9040004436..ddd2f56e7e2f5ae970d94543c642a1d4086192b9 100644
--- a/parser/parser-asap/constraint_conversion.py
+++ b/parser/parser-asap/constraint_conversion.py
@@ -5,6 +5,12 @@ names_plane = {0: 'fix_yz', 1: 'fix_xz', 2: 'fix_xy'}
 names_line = {0: 'fix_x', 1: 'fix_y', 2: 'fix_z'}
 
 def get_index(v):
+    """ Try to guess the Nomad name
+    Parameters:
+        v: (3,) arraylike
+            vector perpedicular to the plane
+            or the direction of the line.
+    """
     v /= np.linalg.norm(v)
     v2 = v * v
     perm = v2.argsort()
@@ -15,11 +21,14 @@ def get_nomad_name(c):
     """This tries to find the appropriate named name from 
     the constaints giving by a direction"""
     constraint = c.todict()
-    if constraint['name'] == 'FixedPlane':
+    name = str(constraint.get('name'))
+    if name == 'FixedPlane':
         d = get_index(c.dir)
         return names_plane[d]
-    elif constraint['name'] == 'FixedLine':
+    elif name == 'FixedLine':
        d = get_index(c.dir)
        return names_line[d]
-    elif constraint['name'] == 'FixedAtoms':
+    elif name == 'FixAtoms':
         return 'fix_xyz'
+    else:
+        return name