diff --git a/aiida_siesta/data/psf.py b/aiida_siesta/data/psf.py
index 7ff6be91..3b939b86 100644
--- a/aiida_siesta/data/psf.py
+++ b/aiida_siesta/data/psf.py
@@ -328,8 +328,13 @@ def get_psf_family_names(self):
         Get the list of all psf family names to which the pseudo belongs
         """
         from aiida.orm import Group
+        from aiida.orm import QueryBuilder
 
-        return [_.name for _ in Group.query(nodes=self, type_string=self.psffamily_type_string)]
+        query = QueryBuilder()
+        query.append(Group, filters={'type_string': {'==': self.psffamily_type_string}}, tag='group', project='label')
+        query.append(PsfData, filters={'id': {'==': self.id}}, with_group='group')
+
+        return [_[0] for _ in query.all()]
 
     @property
     def element(self):
@@ -401,24 +406,23 @@ def get_psf_groups(cls, filter_elements=None, user=None):
                for the username (that is, the user email).
         """
         from aiida.orm import Group
+        from aiida.orm import QueryBuilder
+        from aiida.orm import User
+
+        query = QueryBuilder()
+        filters = {'type_string': {'==': cls.psffamily_type_string}}
 
-        group_query_params = {"type_string": cls.psffamily_type_string}
+        query.append(Group, filters=filters, tag='group', project='*')
 
-        if user is not None:
-            group_query_params['user'] = user
+        if user:
+            query.append(User, filters={'email': {'==': user}}, with_group='group')
 
         if isinstance(filter_elements, str):
             filter_elements = [filter_elements]
 
         if filter_elements is not None:
-            actual_filter_elements = {_.capitalize() for _ in filter_elements}
-
-            group_query_params['node_attributes'] = {'element': actual_filter_elements}
+            query.append(PsfData, filters={'attributes.element': {'in': filter_elements}}, with_group='group')
 
-        all_psf_groups = Group.query(**group_query_params)
+        query.order_by({Group: {'id': 'asc'}})
 
-        groups = [(g.name, g) for g in all_psf_groups]
-        # Sort by name
-        groups.sort()
-        # Return the groups, without name
-        return [_[1] for _ in groups]
+        return [_[0] for _ in query.all()]
diff --git a/aiida_siesta/data/psml.py b/aiida_siesta/data/psml.py
index 8c4f6582..c61c29a5 100644
--- a/aiida_siesta/data/psml.py
+++ b/aiida_siesta/data/psml.py
@@ -329,8 +329,13 @@ def get_psml_family_names(self):
         Get the list of all psml family names to which the pseudo belongs
         """
         from aiida.orm import Group
+        from aiida.orm import QueryBuilder
 
-        return [_.name for _ in Group.query(nodes=self, type_string=self.psmlfamily_type_string)]
+        query = QueryBuilder()
+        query.append(Group, filters={'type_string': {'==': self.psmlfamily_type_string}}, tag='group', project='label')
+        query.append(PsmlData, filters={'id': {'==': self.id}}, with_group='group')
+
+        return [_[0] for _ in query.all()]
 
     @property
     def element(self):
@@ -403,24 +408,23 @@ def get_psml_groups(cls, filter_elements=None, user=None):
                for the username (that is, the user email).
         """
         from aiida.orm import Group
+        from aiida.orm import QueryBuilder
+        from aiida.orm import User
+
+        query = QueryBuilder()
+        filters = {'type_string': {'==': cls.psmlfamily_type_string}}
 
-        group_query_params = {"type_string": cls.psmlfamily_type_string}
+        query.append(Group, filters=filters, tag='group', project='*')
 
-        if user is not None:
-            group_query_params['user'] = user
+        if user:
+            query.append(User, filters={'email': {'==': user}}, with_group='group')
 
         if isinstance(filter_elements, str):
             filter_elements = [filter_elements]
 
         if filter_elements is not None:
-            actual_filter_elements = {_.capitalize() for _ in filter_elements}
-
-            group_query_params['node_attributes'] = {'element': actual_filter_elements}
+            query.append(PsmlData, filters={'attributes.element': {'in': filter_elements}}, with_group='group')
 
-        all_psml_groups = Group.query(**group_query_params)
+        query.order_by({Group: {'id': 'asc'}})
 
-        groups = [(g.name, g) for g in all_psml_groups]
-        # Sort by name
-        groups.sort()
-        # Return the groups, without name
-        return [_[1] for _ in groups]
+        return [_[0] for _ in query.all()]
diff --git a/tests/data/test_pseudos.py b/tests/data/test_pseudos.py
new file mode 100644
index 00000000..2b837a11
--- /dev/null
+++ b/tests/data/test_pseudos.py
@@ -0,0 +1,24 @@
+def test_pseudos_classmethods(generate_psf_data, generate_psml_data):
+
+    from aiida_siesta.data.psml import PsmlData
+    from aiida_siesta.data.psf import PsfData
+
+    assert PsfData.get_psf_groups() == []
+    assert PsmlData.get_psml_groups() == []
+
+    #get_psf_group(cls, group_label)
+
+    #from_md5
+
+    #get_or_create
+
+def test_pseudo(generate_psf_data, generate_psml_data):
+    
+    psf = generate_psf_data('Si')
+    psml = generate_psml_data('Si')
+    
+    assert psf.get_psf_family_names() == []
+    assert psml.get_psml_family_names() == []
+
+    #set_file
+    #assert 'md5' in psf.attributes