Realized that in base64 encoding the default 28 chars will be enough space for anything.

nomad/metainfo/encyclopedia.py

@@ -14,9 +14,8 @@ class Material(MSection):
     material_hash = Quantity(
         type=str,
         description="""
-        A unique material identifier. For crystals the hash
-        identifier is constructed from formula, space group and
-        wyckoff_position_population.
+        A fixed length, unique material identifier in the form of a hash
+        digest.
         """
     )
     system_type = Quantity(
@@ -268,6 +267,30 @@ class Calculation(MSection):
         Mass density of the material based on the structural information.
         """
     )
+    method_hash = Quantity(
+        type=str,
+        description="""
+        A fixed length, unique method identifier in the form of a hash
+        digest.
+        """
+    )
+    group_eos_hash = Quantity(
+        type=str,
+        description="""
+        A fixed length, unique identifier for equation-of-state calculations.
+        Only calculations wihtin the same upload will be grouped under the same
+        hash.
+        """
+    )
+    group_parametervariation_hash = Quantity(
+        type=str,
+        description="""
+        A fixed length, unique identifier for calculations where structure is
+        identical but the used computational parameters are varied.  Only
+        calculations within the same upload will be grouped under the same
+        hash.
+        """
+    )
     run_type = Quantity(
         type=MEnum(
             single_point="single point",

nomad/normalizing/encyclopedia.py

@@ -277,7 +277,7 @@ class Structure():
 
         # Create and store hash based on SHA512
         norm_hash_string = structure.get_symmetry_string(space_group_number, wyckoff_sets)
-        material.material_hash = hash(norm_hash_string, length=128)
+        material.material_hash = hash(norm_hash_string)
 
     def number_of_atoms(self, material: Material, std_atoms: ase.Atoms) -> None:
         material.number_of_atoms = len(std_atoms)
@@ -705,7 +705,7 @@ class Structure1D(Structure):
         id_strings.append(formula)
         id_strings.append(fingerprint)
         hash_seed = ", ".join(id_strings)
-        hash_val = hash(hash_seed, length=128)
+        hash_val = hash(hash_seed)
         material.material_hash = hash_val
 
     def cell_normalized(self, material: Material, std_atoms: ase.Atoms) -> None:
@@ -948,7 +948,7 @@ class Method():
         group_eos_hash = self.group_dict_to_hash('group_eos_hash', hash_dict)
         calculation.group_eos_hash = group_eos_hash
 
-    def group_parametervariation_hash(self):
+    def group_parametervariation_hash(self, calculation: Calculation):
         # Create ordered dictionary with the values. Order is important for
         # consistent hashing.
         hash_dict: OrderedDict = OrderedDict()
@@ -960,7 +960,7 @@ class Method():
 
         # Form a hash from the dictionary
         group_eos_hash = self.group_dict_to_hash('group_eos_hash', hash_dict)
-        calculation.group_eos_hash = group_eos_hash
+        calculation.group_parametervariation_hash = group_eos_hash
 
     def group_e_min(self) -> None:
         pass
@@ -1006,15 +1006,15 @@ class Method():
 
     @abstractmethod
     def method_hash_dict(self):
-        return OrderedDict();
+        return OrderedDict()
 
     @abstractmethod
     def group_eos_hash_dict(self):
-        return OrderedDict();
+        return OrderedDict()
 
     @abstractmethod
     def group_parametervariation_hash_dict(self):
-        return OrderedDict();
+        return OrderedDict()
 
     def group_dict_to_hash(self, name, src_dict: OrderedDict):
         """Given a dictionary of computational settings, this function forms a

nomad/utils.py

@@ -73,7 +73,8 @@ def decode_handle_id(handle_str: str):
 
 
 def hash(*args, length: int = default_hash_len) -> str:
-    """ Creates a websave hash of the given length based on the repr of the given arguments. """
+    """Creates a websave hash of the given length based on the repr of the given arguments.
+    """
     hash = hashlib.sha512()
     for arg in args:
         hash.update(str(arg).encode('utf-8'))
@@ -82,7 +83,8 @@ def hash(*args, length: int = default_hash_len) -> str:
 
 
 def make_websave(hash, length: int = default_hash_len) -> str:
-    """ Creates a websave string for a hashlib hash object. """
+    """Creates a websave string for a hashlib hash object.
+    """
     if length > 0:
         return base64.b64encode(hash.digest(), altchars=b'-_')[:length].decode('utf-8')
     else: