Fixed invalid mapping type.

nomad/datamodel/optimade.py

@@ -173,7 +173,7 @@ class OptimadeEntry(MSection):
     dimension_types = Quantity(
         type=int, shape=[3], default=[0, 0, 0],
         links=optimade_links('h.6.2.8'),
-        a_search=Search(value=lambda a: sum(a.dimension_types), mapping=Integer),
+        a_search=Search(value=lambda a: sum(a.dimension_types), mapping=Integer()),
         a_optimade=Optimade(query=True, entry=True),
         description='''
             List of three integers. For each of the three directions indicated by the three lattice