diff --git a/runschema/__init__.py b/runschema/__init__.py
index 1c51edb..2016bda 100644
--- a/runschema/__init__.py
+++ b/runschema/__init__.py
@@ -22,12 +22,14 @@
 def load_module():
     from . import calculation, system, method, run  # noqa
 
+
 class RunSchemaEntryPoint(SchemaPackageEntryPoint):
     def load(self):
         from .run import m_package
+
         return m_package
 
 
 run_schema_entry_point = RunSchemaEntryPoint(
-    name="RunSchema", description="Schema for the nomad run section."
+    name='RunSchema', description='Schema for the nomad run section.'
 )
diff --git a/runschema/calculation.py b/runschema/calculation.py
index 63eab94..3d5a327 100644
--- a/runschema/calculation.py
+++ b/runschema/calculation.py
@@ -36,6 +36,7 @@
     SubSection,
 )
 from nomad.datamodel.hdf5 import HDF5Dataset
+from nomad.datamodel.metainfo.annotations import H5WebAnnotation
 
 from .method import HoppingMatrix, Method
 from .system import AtomsGroup, System
@@ -1693,7 +1694,10 @@ class Density(Volumetric):
     Section containing the values of the density evaluated on a uniform real-space grid.
     """
 
-    m_def = Section(validate=False)
+    m_def = Section(
+        validate=False,
+        a_h5web=H5WebAnnotation(signal='value_hdf5', title='Charge density'),
+    )
 
     value = Quantity(
         type=np.dtype(np.float64),