diff --git a/src/aiidalab_qe/app/configuration/__init__.py b/src/aiidalab_qe/app/configuration/__init__.py
index 93f24f74f..c71bc1757 100644
--- a/src/aiidalab_qe/app/configuration/__init__.py
+++ b/src/aiidalab_qe/app/configuration/__init__.py
@@ -63,7 +63,7 @@ def __init__(self, model: ConfigurationStepModel, **kwargs):
 
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
 
         self.settings = {
@@ -254,7 +254,7 @@ def _fetch_plugin_calculation_settings(self):
 
             if identifier == "bands":
                 ipw.dlink(
-                    (self._model, "input_structure"),
+                    (self._model, "structure_uuid"),
                     (outline.include, "disabled"),
                     lambda _: not self._model.has_pbc,
                 )
diff --git a/src/aiidalab_qe/app/configuration/advanced/advanced.py b/src/aiidalab_qe/app/configuration/advanced/advanced.py
index 6a3ac96a1..05088ca8b 100644
--- a/src/aiidalab_qe/app/configuration/advanced/advanced.py
+++ b/src/aiidalab_qe/app/configuration/advanced/advanced.py
@@ -79,7 +79,7 @@ def __init__(self, model: AdvancedConfigurationSettingsModel, **kwargs):
 
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
         self._model.observe(
             self._on_spin_type_change,
@@ -150,7 +150,7 @@ def _update_tabs(self):
         self.advanced_tabs.selected_index = 0
 
     def _on_advanced_tab_change(self, change):
-        tab: ConfigurationSettingsPanel = self.advanced_tabs.children[change["new"]]
+        tab: ConfigurationSettingsPanel = self.advanced_tabs.children[change["new"]]  # type: ignore
         tab.render()
 
     def _on_reset_to_defaults_button_click(self, _):
diff --git a/src/aiidalab_qe/app/configuration/advanced/convergence/convergence.py b/src/aiidalab_qe/app/configuration/advanced/convergence/convergence.py
index 393d55b4f..910ee6799 100644
--- a/src/aiidalab_qe/app/configuration/advanced/convergence/convergence.py
+++ b/src/aiidalab_qe/app/configuration/advanced/convergence/convergence.py
@@ -13,8 +13,8 @@ def __init__(self, model: ConvergenceConfigurationSettingsModel, **kwargs):
         super().__init__(model, **kwargs)
 
         self._model.observe(
-            self._on_structure_change,
-            "input_structure",
+            self._on_input_structure_change,
+            "structure_uuid",
         )
         self._model.observe(
             self._on_protocol_change,
@@ -107,7 +107,7 @@ def render(self):
             (self.kpoints_distance, "value"),
         )
         ipw.dlink(
-            (self._model, "input_structure"),
+            (self._model, "structure_uuid"),
             (self.kpoints_distance, "disabled"),
             lambda _: not self._model.has_pbc,
         )
@@ -239,7 +239,7 @@ def render(self):
 
         self.rendered = True
 
-    def _on_structure_change(self, _):
+    def _on_input_structure_change(self, _):
         self.refresh(specific="structure")
 
     def _on_protocol_change(self, _):
diff --git a/src/aiidalab_qe/app/configuration/advanced/convergence/model.py b/src/aiidalab_qe/app/configuration/advanced/convergence/model.py
index 64906612b..0a041887d 100644
--- a/src/aiidalab_qe/app/configuration/advanced/convergence/model.py
+++ b/src/aiidalab_qe/app/configuration/advanced/convergence/model.py
@@ -20,7 +20,7 @@ class ConvergenceConfigurationSettingsModel(
     identifier = "convergence"
 
     dependencies = [
-        "input_structure",
+        "structure_uuid",
         "protocol",
     ]
 
diff --git a/src/aiidalab_qe/app/configuration/advanced/hubbard/hubbard.py b/src/aiidalab_qe/app/configuration/advanced/hubbard/hubbard.py
index ce8f3624d..e12519481 100644
--- a/src/aiidalab_qe/app/configuration/advanced/hubbard/hubbard.py
+++ b/src/aiidalab_qe/app/configuration/advanced/hubbard/hubbard.py
@@ -14,7 +14,7 @@ def __init__(self, model: HubbardConfigurationSettingsModel, **kwargs):
 
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
         self._model.observe(
             self._on_hubbard_activation,
diff --git a/src/aiidalab_qe/app/configuration/advanced/hubbard/model.py b/src/aiidalab_qe/app/configuration/advanced/hubbard/model.py
index 205993075..ed6682bda 100644
--- a/src/aiidalab_qe/app/configuration/advanced/hubbard/model.py
+++ b/src/aiidalab_qe/app/configuration/advanced/hubbard/model.py
@@ -19,7 +19,7 @@ class HubbardConfigurationSettingsModel(
     identifier = "hubbard"
 
     dependencies = [
-        "input_structure",
+        "structure_uuid",
     ]
 
     is_active = tl.Bool(False)
@@ -95,7 +95,7 @@ def set_active_eigenvalues(self, eigenvalues: list):
         self.has_eigenvalues = True
 
     def get_parameters_from_hubbard_structure(self):
-        hubbard_parameters = self.input_structure.hubbard.dict()["parameters"]
+        hubbard_parameters = self.input_structure.hubbard.model_dump()["parameters"]
         sites = self.input_structure.sites
         return {
             f"{sites[hp['atom_index']].kind_name} - {hp['atom_manifold']}": hp["value"]
diff --git a/src/aiidalab_qe/app/configuration/advanced/magnetization/magnetization.py b/src/aiidalab_qe/app/configuration/advanced/magnetization/magnetization.py
index 4e6d80940..a96825e70 100644
--- a/src/aiidalab_qe/app/configuration/advanced/magnetization/magnetization.py
+++ b/src/aiidalab_qe/app/configuration/advanced/magnetization/magnetization.py
@@ -27,7 +27,7 @@ def __init__(self, model: MagnetizationConfigurationSettingsModel, **kwargs):
 
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
         self._model.observe(
             self._on_electronic_type_change,
@@ -151,7 +151,7 @@ def _build_kinds_widget(self):
 
         kind_names = (
             self._model.input_structure.get_kind_names()
-            if self._model.input_structure
+            if self._model.has_structure
             else []
         )
 
diff --git a/src/aiidalab_qe/app/configuration/advanced/magnetization/model.py b/src/aiidalab_qe/app/configuration/advanced/magnetization/model.py
index bd76cc7ec..88241ff19 100644
--- a/src/aiidalab_qe/app/configuration/advanced/magnetization/model.py
+++ b/src/aiidalab_qe/app/configuration/advanced/magnetization/model.py
@@ -18,7 +18,7 @@ class MagnetizationConfigurationSettingsModel(
     identifier = "magnetization"
 
     dependencies = [
-        "input_structure",
+        "structure_uuid",
         "electronic_type",
         "spin_type",
         "pseudos.dictionary",
diff --git a/src/aiidalab_qe/app/configuration/advanced/model.py b/src/aiidalab_qe/app/configuration/advanced/model.py
index 1af5ac9d7..e484d502d 100644
--- a/src/aiidalab_qe/app/configuration/advanced/model.py
+++ b/src/aiidalab_qe/app/configuration/advanced/model.py
@@ -26,7 +26,7 @@ class AdvancedConfigurationSettingsModel(
     identifier = "advanced"
 
     dependencies = [
-        "input_structure",
+        "structure_uuid",
         "workchain.protocol",
         "workchain.spin_type",
         "workchain.electronic_type",
@@ -233,7 +233,7 @@ def _set_pw_parameters(self, pw_parameters):
         control_params: dict = pw_parameters.get("CONTROL", {})
         electron_params: dict = pw_parameters.get("ELECTRONS", {})
 
-        num_atoms = len(self.input_structure.sites) if self.input_structure else 1
+        num_atoms = len(self.input_structure.sites) if self.has_structure else 1
 
         general = t.cast(
             GeneralConfigurationSettingsModel,
diff --git a/src/aiidalab_qe/app/configuration/advanced/pseudos/model.py b/src/aiidalab_qe/app/configuration/advanced/pseudos/model.py
index a16bfc2ac..a8239f573 100644
--- a/src/aiidalab_qe/app/configuration/advanced/pseudos/model.py
+++ b/src/aiidalab_qe/app/configuration/advanced/pseudos/model.py
@@ -31,7 +31,7 @@ class PseudosConfigurationSettingsModel(
     identifier = "pseudos"
 
     dependencies = [
-        "input_structure",
+        "structure_uuid",
         "protocol",
         "spin_orbit",
     ]
@@ -249,7 +249,7 @@ def update_cutoffs(self):
         if self.locked or not self.dictionary:
             return
 
-        kinds = self.input_structure.kinds if self.input_structure else []
+        kinds = self.input_structure.kinds if self.has_structure else []
         self.status_message = ""
 
         if self.family:
diff --git a/src/aiidalab_qe/app/configuration/advanced/pseudos/pseudos.py b/src/aiidalab_qe/app/configuration/advanced/pseudos/pseudos.py
index 37749326b..e48f90908 100644
--- a/src/aiidalab_qe/app/configuration/advanced/pseudos/pseudos.py
+++ b/src/aiidalab_qe/app/configuration/advanced/pseudos/pseudos.py
@@ -22,7 +22,7 @@ def __init__(self, model: PseudosConfigurationSettingsModel, **kwargs):
 
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
         self._model.observe(
             self._on_protocol_change,
diff --git a/src/aiidalab_qe/app/configuration/basic/basic.py b/src/aiidalab_qe/app/configuration/basic/basic.py
index e1d24c269..792257132 100644
--- a/src/aiidalab_qe/app/configuration/basic/basic.py
+++ b/src/aiidalab_qe/app/configuration/basic/basic.py
@@ -17,7 +17,7 @@ def __init__(self, model: BasicConfigurationSettingsModel, **kwargs):
         super().__init__(model, **kwargs)
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
 
     def render(self):
diff --git a/src/aiidalab_qe/app/configuration/basic/model.py b/src/aiidalab_qe/app/configuration/basic/model.py
index 0d8a91392..06a2b51b4 100644
--- a/src/aiidalab_qe/app/configuration/basic/model.py
+++ b/src/aiidalab_qe/app/configuration/basic/model.py
@@ -20,7 +20,7 @@ class BasicConfigurationSettingsModel(
     identifier = "workchain"
 
     dependencies = [
-        "input_structure",
+        "structure_uuid",
     ]
 
     protocol_options = tl.List(
diff --git a/src/aiidalab_qe/app/result/__init__.py b/src/aiidalab_qe/app/result/__init__.py
index 480944510..96faef671 100644
--- a/src/aiidalab_qe/app/result/__init__.py
+++ b/src/aiidalab_qe/app/result/__init__.py
@@ -121,7 +121,7 @@ def _post_render(self):
 
         self.toggle_controls.value = (
             "Results"
-            if (process := self._model.fetch_process_node()) and process.is_finished_ok
+            if self._model.has_process and self._model.process.is_finished_ok
             else "Status"
         )
 
@@ -152,10 +152,9 @@ def _on_state_change(self, change):
 
     def _on_previous_step_state_change(self, _):
         if self.previous_step_state is WizardAppWidgetStep.State.SUCCESS:
-            process_node = self._model.fetch_process_node()
             message = (
                 "Loading results"
-                if process_node and process_node.is_finished
+                if self._model.has_process and self._model.process.is_finished
                 else "Submitting calculation"
             )
             self.children = [LoadingWidget(message)]
@@ -203,11 +202,10 @@ def _toggle_view(self, panel: ResultsComponent):
     def _update_kill_button_layout(self):
         if not self.rendered:
             return
-        process_node = self._model.fetch_process_node()
         if (
-            not process_node
-            or process_node.is_finished
-            or process_node.is_excepted
+            not self._model.has_process
+            or self._model.process.is_finished
+            or self._model.process.is_excepted
             or self.state
             in (
                 self.State.SUCCESS,
@@ -221,8 +219,7 @@ def _update_kill_button_layout(self):
     def _update_clean_scratch_button_layout(self):
         if not self.rendered:
             return
-        process_node = self._model.fetch_process_node()
-        if process_node and process_node.is_terminated:
+        if self._model.has_process and self._model.process.is_terminated:
             self.clean_scratch_button.layout.display = "block"
         else:
             self.clean_scratch_button.layout.display = "none"
@@ -231,12 +228,12 @@ def _update_status(self):
         self._model.monitor_counter += 1
 
     def _update_state(self):
-        if not (process_node := self._model.fetch_process_node()):
+        if not self._model.has_process:
             self.state = self.State.INIT
             self._update_controls()
             return
 
-        if process_state := process_node.process_state:
+        if process_state := self._model.process.process_state:
             status = self._get_process_status(process_state.value)
         else:
             status = "Unknown"
@@ -254,9 +251,9 @@ def _update_state(self):
             ProcessState.KILLED,
         ):
             self.state = self.State.FAIL
-        elif process_node.is_failed:
+        elif self._model.process.is_failed:
             self.state = self.State.FAIL
-        elif process_node.is_finished_ok:
+        elif self._model.process.is_finished_ok:
             self.state = self.State.SUCCESS
 
         self._model.process_info = self.STATUS_TEMPLATE.format(status)
diff --git a/src/aiidalab_qe/app/result/components/summary/model.py b/src/aiidalab_qe/app/result/components/summary/model.py
index f83097047..10b9b41ce 100644
--- a/src/aiidalab_qe/app/result/components/summary/model.py
+++ b/src/aiidalab_qe/app/result/components/summary/model.py
@@ -124,16 +124,15 @@ def generate_report_text(self, report_dict):
 
     def generate_failure_report(self):
         """Generate a html for reporting the failure of the `QeAppWorkChain`."""
-        process_node = self.fetch_process_node()
-        if not (process_node and process_node.exit_status):
+        if not (self.has_process and self.process.exit_status):
             return
-        final_calcjob = self._get_final_calcjob(process_node)
+        final_calcjob = self._get_final_calcjob(self.process)
         env = Environment()
         template = files(templates).joinpath("workflow_failure.jinja").read_text()
         style = files(styles).joinpath("style.css").read_text()
         self.failed_calculation_report = env.from_string(template).render(
             style=style,
-            process_report=get_workchain_report(process_node, "REPORT"),
+            process_report=get_workchain_report(self.process, "REPORT"),
             calcjob_exit_message=final_calcjob.exit_message,
         )
         self.has_failure_report = True
@@ -151,9 +150,7 @@ def _generate_report_parameters(self):
         """
         from aiida.orm.utils.serialize import deserialize_unsafe
 
-        qeapp_wc = self.fetch_process_node()
-
-        ui_parameters = qeapp_wc.base.extras.get("ui_parameters", {})
+        ui_parameters = self.process.base.extras.get("ui_parameters", {})
         if isinstance(ui_parameters, str):
             ui_parameters = deserialize_unsafe(ui_parameters)
         # Construct the report parameters needed for the report
@@ -161,19 +158,20 @@ def _generate_report_parameters(self):
         if "workchain" not in ui_parameters:
             return {}
 
-        inputs = qeapp_wc.inputs
+        inputs = self.inputs
+        assert inputs.structure, "BUG! Missing structure input"  # shouldn't happen!
         structure: orm.StructureData = inputs.structure
         basic = ui_parameters["workchain"]
         advanced = ui_parameters["advanced"]
-        ctime = qeapp_wc.ctime
-        mtime = qeapp_wc.mtime
+        ctime = self.process.ctime
+        mtime = self.process.mtime
 
         report = {
             "workflow_properties": {
-                "pk": qeapp_wc.pk,
-                "uuid": str(qeapp_wc.uuid),
-                "label": qeapp_wc.label,
-                "description": qeapp_wc.description,
+                "pk": self.process.pk,
+                "uuid": str(self.process.uuid),
+                "label": self.process.label,
+                "description": self.process.description,
                 "creation_time": f"{format_time(ctime)} ({relative_time(ctime)})",
                 "modification_time": f"{format_time(mtime)} ({relative_time(mtime)})",
             },
diff --git a/src/aiidalab_qe/app/result/components/summary/summary.py b/src/aiidalab_qe/app/result/components/summary/summary.py
index 71028c0d1..28563320c 100644
--- a/src/aiidalab_qe/app/result/components/summary/summary.py
+++ b/src/aiidalab_qe/app/result/components/summary/summary.py
@@ -81,9 +81,8 @@ def _render_summary(self):
         self.has_settings_report = True
 
     def _render_download_widget(self):
-        process_node = self._model.fetch_process_node()
-        if process_node and process_node.is_terminated:
-            output_download_widget = WorkChainOutputs(node=process_node)
+        if self._model.has_process and self._model.process.is_terminated:
+            output_download_widget = WorkChainOutputs(node=self._model.process)
             output_download_widget.layout.width = "100%"
             self.output_download_container.children = [
                 self.output_download_help,
diff --git a/src/aiidalab_qe/app/result/model.py b/src/aiidalab_qe/app/result/model.py
index c6b6c5564..bc19a66e0 100644
--- a/src/aiidalab_qe/app/result/model.py
+++ b/src/aiidalab_qe/app/result/model.py
@@ -26,13 +26,13 @@ def update(self):
         self._update_process_remote_folder_state()
 
     def kill_process(self):
-        if process_node := self.fetch_process_node():
-            control.kill_processes([process_node])
+        if self.has_process:
+            control.kill_processes([self.process])
 
     def clean_remote_data(self):
-        if not (process_node := self.fetch_process_node()):
+        if not self.has_process:
             return
-        for called_descendant in process_node.called_descendants:
+        for called_descendant in self.process.called_descendants:
             if isinstance(called_descendant, orm.CalcJobNode):
                 with contextlib.suppress(Exception):
                     called_descendant.outputs.remote_folder._clean()
@@ -43,11 +43,10 @@ def reset(self):
         self.process_info = ""
 
     def _update_process_remote_folder_state(self):
-        process_node = self.fetch_process_node()
-        if not (process_node and process_node.called_descendants):
+        if not (self.has_process and self.process.called_descendants):
             return
         cleaned = []
-        for called_descendant in process_node.called_descendants:
+        for called_descendant in self.process.called_descendants:
             if isinstance(called_descendant, orm.CalcJobNode):
                 with contextlib.suppress(Exception):
                     cleaned.append(called_descendant.outputs.remote_folder.is_empty)
diff --git a/src/aiidalab_qe/app/structure/__init__.py b/src/aiidalab_qe/app/structure/__init__.py
index 0c3750d9a..784533002 100644
--- a/src/aiidalab_qe/app/structure/__init__.py
+++ b/src/aiidalab_qe/app/structure/__init__.py
@@ -17,6 +17,7 @@
     ShakeNBreakEditor,
 )
 from aiidalab_qe.common.infobox import InAppGuide
+from aiidalab_qe.common.setup_pseudos import PseudosInstallWidget
 from aiidalab_qe.common.widgets import CategorizedStructureExamplesWidget
 from aiidalab_qe.common.wizard import QeConfirmableWizardStep
 from aiidalab_widgets_base import (
@@ -66,7 +67,7 @@ def __init__(self, model: StructureStepModel, auto_setup=True, **kwargs):
         )
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
         self._install_sssp(auto_setup)
 
@@ -133,7 +134,8 @@ def _render(self):
 
         ipw.dlink(
             (self.manager, "structure_node"),
-            (self._model, "input_structure"),
+            (self._model, "structure_uuid"),
+            lambda node: node.uuid if node else None,
         )
         ipw.link(
             (self._model, "manager_output"),
@@ -198,8 +200,6 @@ def _on_input_structure_change(self, _):
         self._update_state()
 
     def _install_sssp(self, auto_setup):
-        from aiidalab_qe.common.setup_pseudos import PseudosInstallWidget
-
         self.sssp_installation = PseudosInstallWidget(auto_start=False)
         ipw.dlink(
             (self.sssp_installation, "busy"),
@@ -224,7 +224,7 @@ def _toggle_sssp_installation_widget(self):
     def _update_state(self):
         if self._model.confirmed:
             self.state = self.State.SUCCESS
-        elif self._model.input_structure is None:
+        elif not self._model.has_structure:
             self.state = self.State.READY
         else:
             self.state = self.State.CONFIGURED
diff --git a/src/aiidalab_qe/app/structure/model.py b/src/aiidalab_qe/app/structure/model.py
index 25b264d19..b2b846a7d 100644
--- a/src/aiidalab_qe/app/structure/model.py
+++ b/src/aiidalab_qe/app/structure/model.py
@@ -31,7 +31,7 @@ def update_widget_text(self):
             self.structure_name = str(self.input_structure.get_formula())
 
     def reset(self):
-        self.input_structure = None
+        self.structure_uuid = None
         self.structure_name = ""
         self.manager_output = ""
 
diff --git a/src/aiidalab_qe/app/submission/__init__.py b/src/aiidalab_qe/app/submission/__init__.py
index f58627a0a..c3e1a4b1a 100644
--- a/src/aiidalab_qe/app/submission/__init__.py
+++ b/src/aiidalab_qe/app/submission/__init__.py
@@ -73,6 +73,10 @@ def __init__(self, model: SubmissionStepModel, auto_setup=True, **kwargs):
             self._on_input_parameters_change,
             "input_parameters",
         )
+        self._model.observe(
+            self._on_process_change,
+            "process_uuid",
+        )
 
         self.settings = {
             "global": self.global_resources,
@@ -210,6 +214,9 @@ def _on_qe_installed(self, _):
         if self._model.qe_installed:
             self._model.update()
 
+    def _on_process_change(self, _):
+        self._model.update_process_metadata()
+
     def _set_up_qe(self, auto_setup):
         self.qe_setup = QESetupWidget(auto_start=False)
         ipw.dlink(
diff --git a/src/aiidalab_qe/app/submission/global_settings/model.py b/src/aiidalab_qe/app/submission/global_settings/model.py
index 3c5f82f1b..d7dae2212 100644
--- a/src/aiidalab_qe/app/submission/global_settings/model.py
+++ b/src/aiidalab_qe/app/submission/global_settings/model.py
@@ -20,7 +20,7 @@ class GlobalResourceSettingsModel(
     identifier = "global"
 
     dependencies = [
-        "input_structure",
+        "structure_uuid",
         "input_parameters",
     ]
 
diff --git a/src/aiidalab_qe/app/submission/global_settings/setting.py b/src/aiidalab_qe/app/submission/global_settings/setting.py
index 8955e97ba..05b32e4f8 100644
--- a/src/aiidalab_qe/app/submission/global_settings/setting.py
+++ b/src/aiidalab_qe/app/submission/global_settings/setting.py
@@ -20,7 +20,7 @@ def __init__(self, model: GlobalResourceSettingsModel, **kwargs):
 
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
         self._model.observe(
             self._on_input_parameters_change,
diff --git a/src/aiidalab_qe/app/submission/model.py b/src/aiidalab_qe/app/submission/model.py
index b70a50447..f10c38b9c 100644
--- a/src/aiidalab_qe/app/submission/model.py
+++ b/src/aiidalab_qe/app/submission/model.py
@@ -8,7 +8,7 @@
 from aiida.engine import ProcessBuilderNamespace, submit
 from aiida.orm.utils.serialize import serialize
 from aiidalab_qe.app.parameters import DEFAULT_PARAMETERS
-from aiidalab_qe.common.mixins import HasInputStructure, HasModels
+from aiidalab_qe.common.mixins import HasInputStructure, HasModels, HasProcess
 from aiidalab_qe.common.panel import PluginResourceSettingsModel, ResourceSettingsModel
 from aiidalab_qe.common.wizard import QeConfirmableWizardStepModel
 from aiidalab_qe.utils import shallow_copy_nested_dict
@@ -21,12 +21,12 @@ class SubmissionStepModel(
     QeConfirmableWizardStepModel,
     HasModels[ResourceSettingsModel],
     HasInputStructure,
+    HasProcess,
 ):
     identifier = "submission"
 
     input_parameters = tl.Dict()
 
-    process_node = tl.Instance(orm.WorkChainNode, allow_none=True)
     process_label = tl.Unicode("")
     process_description = tl.Unicode("")
 
@@ -62,7 +62,7 @@ def __init__(self, *args, **kwargs):
 
     def confirm(self):
         super().confirm()
-        if not self.process_node:
+        if not self.has_process:
             self._submit()
 
     def update(self):
@@ -70,7 +70,7 @@ def update(self):
             model.update()
 
     def update_process_label(self):
-        if not self.input_structure:
+        if not self.has_structure:
             self.process_label = ""
             return
         structure_label = (
@@ -165,16 +165,17 @@ def set_model_state(self, state: dict):
                 model.set_model_state(codes[identifier])
                 model.locked = True
 
-        if self.process_node:
-            self.process_label = self.process_node.label
-            self.process_description = self.process_node.description
-            self.locked = True
+    def update_process_metadata(self):
+        if not self.has_process:
+            return
+        self.process_label = self.process.label
+        self.process_description = self.process.description
+        self.locked = True
 
     def reset(self):
         with self.hold_trait_notifications():
-            self.input_structure = None
             self.input_parameters = {}
-            self.process_node = None
+            self.process_uuid = None
             for identifier, model in self.get_models():
                 if identifier not in self._default_models:
                     model.include = False
@@ -197,13 +198,10 @@ def _submit(self):
                 "structure",
                 self.input_structure.get_formula(),
             )
-            self.process_node = process_node
-
-            self._update_url()
+            self.process_uuid = process_node.uuid
 
-    def _update_url(self):
-        pk = self.process_node.pk
-        display(Javascript(f"window.history.pushState(null, '', '?pk={pk}');"))
+            pk = process_node.pk
+            display(Javascript(f"window.history.pushState(null, '', '?pk={pk}');"))
 
     def _link_model(self, model: ResourceSettingsModel):
         for dependency in model.dependencies:
diff --git a/src/aiidalab_qe/app/wizard_app.py b/src/aiidalab_qe/app/wizard_app.py
index 106355464..7a56bf93c 100644
--- a/src/aiidalab_qe/app/wizard_app.py
+++ b/src/aiidalab_qe/app/wizard_app.py
@@ -145,23 +145,22 @@ def _render_step(self, step_index):
 
     def _update_configuration_step(self):
         if self.structure_model.confirmed:
-            self.configure_model.input_structure = self.structure_model.input_structure
+            self.configure_model.structure_uuid = self.structure_model.structure_uuid
         else:
-            self.configure_model.input_structure = None
+            self.configure_model.structure_uuid = None
 
     def _update_submission_step(self):
         if self.configure_model.confirmed:
-            self.submit_model.input_structure = self.structure_model.input_structure
+            self.submit_model.structure_uuid = self.structure_model.structure_uuid
             self.submit_model.input_parameters = self.configure_model.get_model_state()
         else:
-            self.submit_model.input_structure = None
+            self.submit_model.structure_uuid = None
             self.submit_model.input_parameters = {}
 
     def _update_results_step(self):
         ipw.dlink(
-            (self.submit_model, "process_node"),
+            (self.submit_model, "process_uuid"),
             (self.results_model, "process_uuid"),
-            lambda node: node.uuid if node is not None else None,
         )
 
     def _lock_app(self):
@@ -179,14 +178,14 @@ def _update_from_process(self, pk):
         else:
             self._show_process_loading_message()
             process_node = load_node(pk)
-            self.structure_model.input_structure = process_node.inputs.structure
+            self.structure_model.structure_uuid = process_node.inputs.structure.uuid
             self.structure_model.confirm()
             parameters = process_node.base.extras.get("ui_parameters", {})
             if parameters and isinstance(parameters, str):
                 parameters = deserialize_unsafe(parameters)
             self.configure_model.set_model_state(parameters)
             self.configure_model.confirm()
-            self.submit_model.process_node = process_node
+            self.submit_model.process_uuid = process_node.uuid
             self.submit_model.set_model_state(parameters)
             self.submit_model.confirm()
             self._wizard_app_widget.selected_index = 3
diff --git a/src/aiidalab_qe/common/mixins.py b/src/aiidalab_qe/common/mixins.py
index 124666ddc..74c1a9da9 100644
--- a/src/aiidalab_qe/common/mixins.py
+++ b/src/aiidalab_qe/common/mixins.py
@@ -9,15 +9,20 @@
 from aiida_quantumespresso.data.hubbard_structure import HubbardStructureData
 from aiidalab_qe.common.mvc import Model
 
+StructureType = t.Union[orm.StructureData, HubbardStructureData]
+
 
 class HasInputStructure(tl.HasTraits):
-    input_structure = tl.Union(
-        [
-            tl.Instance(orm.StructureData),
-            tl.Instance(HubbardStructureData),
-        ],
-        allow_none=True,
-    )
+    structure_uuid = tl.Unicode(None, allow_none=True)
+
+    @property
+    def input_structure(self) -> StructureType | None:
+        if not self.structure_uuid:
+            return None
+        try:
+            return t.cast(StructureType, orm.load_node(self.structure_uuid))
+        except NotExistent:
+            return None
 
     @property
     def has_structure(self):
@@ -29,7 +34,7 @@ def has_pbc(self):
 
     @property
     def has_tags(self):
-        return any(
+        return self.has_structure and any(
             not kind_name.isalpha()
             for kind_name in self.input_structure.get_kind_names()
         )
@@ -99,36 +104,36 @@ class HasProcess(tl.HasTraits):
     process_uuid = tl.Unicode(None, allow_none=True)
     monitor_counter = tl.Int(0)  # used for continuous updates
 
+    @property
+    def process(self) -> orm.WorkChainNode | None:
+        if not self.process_uuid:
+            return None
+        try:
+            return t.cast(orm.WorkChainNode, orm.load_node(self.process_uuid))
+        except NotExistent:
+            return None
+
     @property
     def has_process(self):
-        return self.fetch_process_node() is not None
+        return self.process is not None
 
     @property
-    def inputs(self):
-        process_node = self.fetch_process_node()
-        return process_node.inputs if process_node else []
+    def inputs(self) -> orm.NodeLinksManager | list:
+        return self.process.inputs if self.has_process else []
 
     @property
-    def properties(self):
-        process_node = self.fetch_process_node()
+    def properties(self) -> list:
         # read the attributes directly instead of using the `get_list` method
         # to avoid error in case of the orm.List object being converted to a orm.Data object
         return (
-            process_node.inputs.properties.base.attributes.get("list")
-            if process_node
+            self.inputs.properties.base.attributes.get("list")
+            if self.has_process
             else []
         )
 
     @property
     def outputs(self):
-        process_node = self.fetch_process_node()
-        return process_node.outputs if process_node else []
-
-    def fetch_process_node(self) -> orm.ProcessNode | None:
-        try:
-            return orm.load_node(self.process_uuid) if self.process_uuid else None  # type: ignore
-        except NotExistent:
-            return None
+        return self.process.outputs if self.has_process else []
 
 
 class Confirmable(tl.HasTraits):
diff --git a/src/aiidalab_qe/common/panel.py b/src/aiidalab_qe/common/panel.py
index 7ed6f862b..a32839422 100644
--- a/src/aiidalab_qe/common/panel.py
+++ b/src/aiidalab_qe/common/panel.py
@@ -526,22 +526,20 @@ def fetch_child_process_node(self, which="this") -> orm.ProcessNode | None:
         uuid = getattr(self, f"_{which}_process_uuid")
         label = getattr(self, f"_{which}_process_label")
         if not uuid:
-            root = self.fetch_process_node()
+            root = self.process
             child = next((c for c in root.called if c.process_label == label), None)
             uuid = child.uuid if child else None
         return orm.load_node(uuid) if uuid else None  # type: ignore
 
     def save_state(self):
         """Saves the current state of the model to the AiiDA database."""
-        node = self.fetch_process_node()
-        results = node.base.extras.get("results", {})
+        results = self.process.base.extras.get("results", {})
         results[self.identifier] = self.get_model_state()
-        node.base.extras.set("results", results)
+        self.process.base.extras.set("results", results)
 
     def load_state(self):
         """Loads the state of the model from the AiiDA database."""
-        node = self.fetch_process_node()
-        results = node.base.extras.get("results", {})
+        results = self.process.base.extras.get("results", {})
         if self.identifier in results:
             self.set_model_state(results[self.identifier])
 
diff --git a/src/aiidalab_qe/common/process/tree.py b/src/aiidalab_qe/common/process/tree.py
index 98632c678..4ed0b9eef 100644
--- a/src/aiidalab_qe/common/process/tree.py
+++ b/src/aiidalab_qe/common/process/tree.py
@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-import threading
 import typing as t
 from copy import deepcopy
 
@@ -8,6 +7,7 @@
 import traitlets as tl
 
 from aiida import orm
+from aiida.common.exceptions import NotExistent
 from aiida.common.links import LinkType
 from aiida.engine import ProcessState
 from aiida.tools.graph.graph_traversers import traverse_graph
@@ -102,9 +102,10 @@ def _render(self):
         )
         self.collapse_button.on_click(self._collapse_all)
 
-        root = self._model.fetch_process_node()
-
-        self.trunk = WorkChainTreeNode(node=root, on_inspect=self._on_inspect)
+        self.trunk = WorkChainTreeNode(
+            node=self._model.process,
+            on_inspect=self._on_inspect,
+        )
         self.trunk.add_class("tree-trunk")
         self.trunk.initialize()
         self.trunk.expand()
@@ -157,18 +158,19 @@ def __init__(
         on_inspect: t.Callable[[str], None] | None = None,
         **kwargs,
     ):
-        self.uuid = node.uuid
+        self.process_uuid = node.uuid
         self.level = level
         self.on_inspect = on_inspect
         super().__init__(**kwargs)
-        self._node: dict[int, ProcessNodeType] = {}  # thread_id: node
 
     @property
-    def node(self) -> ProcessNodeType:
-        if (tid := threading.get_ident()) not in self._node:
-            node = orm.load_node(self.uuid)
-            self._node[tid] = node
-        return self._node[tid]
+    def process(self) -> ProcessNodeType | None:
+        if not self.process_uuid:
+            return None
+        try:
+            return t.cast(ProcessNodeType, orm.load_node(self.process_uuid))
+        except NotExistent:
+            return None
 
     def initialize(self):
         self._build_header()
@@ -193,11 +195,11 @@ def _get_emoji(self, state):
         return STATE_ICONS.get(state, "❓")
 
     def _get_state(self):
-        if not hasattr(self.node, "process_state"):
+        if not hasattr(self.process, "process_state"):
             return "queued"
-        if self.node.is_failed:
+        if self.process.is_failed:
             return "failed"
-        state = self.node.process_state
+        state = self.process.process_state
         return (
             "running"
             if state is ProcessState.WAITING
@@ -207,7 +209,7 @@ def _get_state(self):
         )
 
     def _get_human_readable_title(self):
-        node = self.node
+        node = self.process
         if not (label := node.process_label):
             return "Unknown"
         if label in ("PwBaseWorkChain", "PwCalculation"):
@@ -249,12 +251,12 @@ def metadata_inputs(self):
         # summary to extract pw parameters. #1163 removes this dependency, thus allowing
         # the popping of the "relax" port if not running relaxation. However, this is
         # kept for backwards compatibility, for jobs ran before #1163.
-        inputs = deepcopy(self.node.get_metadata_inputs()) or {}
-        if "properties" in self.node.inputs:
+        inputs = deepcopy(self.process.get_metadata_inputs()) or {}
+        if "properties" in self.process.inputs:
             inputs = {
                 key: value
                 for key, value in inputs.items()
-                if key in self.node.inputs.properties.base.attributes.get("list")
+                if key in self.process.inputs.properties.base.attributes.get("list")
             }
         return inputs
 
@@ -332,9 +334,9 @@ def _add_branches(self):
         self._add_branches_recursive()
         self._adding_branches = False
 
-    def _add_branches_recursive(self, node: orm.ProcessNode | None = None):
-        node = node or self.node
-        for child in sorted(node.called, key=lambda child: child.ctime):
+    def _add_branches_recursive(self, process: orm.ProcessNode | None = None):
+        process = process or self.process
+        for child in sorted(process.called, key=lambda child: child.ctime):
             if isinstance(child, orm.CalcFunctionNode):
                 continue
             if child.pk in self.pks:
@@ -373,7 +375,7 @@ def _get_tally(self):
 
     def _count_finished(self):
         traverser = traverse_graph(
-            starting_pks=[self.node.pk],
+            starting_pks=[self.process.pk],
             links_forward=[
                 LinkType.CALL_WORK,
                 LinkType.CALL_CALC,
@@ -450,4 +452,4 @@ def _build_header(self):
     def _on_label_click(self, _):
         if self.on_inspect is None:
             return
-        self.on_inspect(self.uuid)
+        self.on_inspect(self.process_uuid)
diff --git a/src/aiidalab_qe/plugins/electronic_structure/result/result.py b/src/aiidalab_qe/plugins/electronic_structure/result/result.py
index 8eb10e322..c51456b1d 100644
--- a/src/aiidalab_qe/plugins/electronic_structure/result/result.py
+++ b/src/aiidalab_qe/plugins/electronic_structure/result/result.py
@@ -100,7 +100,7 @@ def _render_bands_pdos_widget(self, node_identifiers):
                 identifier: self._model.fetch_child_process_node(identifier)
                 for identifier in node_identifiers
             },
-            "root": self._model.fetch_process_node(),
+            "root": self._model.process,
         }
         model = BandsPdosModel.from_nodes(**nodes)
         widget = BandsPdosWidget(model=model)
diff --git a/src/aiidalab_qe/plugins/pdos/model.py b/src/aiidalab_qe/plugins/pdos/model.py
index 9f5b08ea0..5de6bdb9d 100644
--- a/src/aiidalab_qe/plugins/pdos/model.py
+++ b/src/aiidalab_qe/plugins/pdos/model.py
@@ -14,7 +14,7 @@ class PdosConfigurationSettingsModel(PanelModel, HasInputStructure):
     identifier = "pdos"
 
     dependencies = [
-        "input_structure",
+        "structure_uuid",
         "workchain.protocol",
     ]
 
diff --git a/src/aiidalab_qe/plugins/pdos/setting.py b/src/aiidalab_qe/plugins/pdos/setting.py
index ce3e1e243..c05000541 100644
--- a/src/aiidalab_qe/plugins/pdos/setting.py
+++ b/src/aiidalab_qe/plugins/pdos/setting.py
@@ -18,7 +18,7 @@ def __init__(self, model: PdosConfigurationSettingsModel, **kwargs):
 
         self._model.observe(
             self._on_input_structure_change,
-            "input_structure",
+            "structure_uuid",
         )
         self._model.observe(
             self._on_protocol_change,
@@ -44,7 +44,7 @@ def render(self):
             (self.nscf_kpoints_distance, "value"),
         )
         ipw.dlink(
-            (self._model, "input_structure"),
+            (self._model, "structure_uuid"),
             (self.nscf_kpoints_distance, "disabled"),
             lambda _: not self._model.has_pbc,
         )
@@ -65,7 +65,7 @@ def render(self):
             (self.use_pdos_degauss, "value"),
         )
         ipw.dlink(
-            (self._model, "input_structure"),
+            (self._model, "structure_uuid"),
             (self.use_pdos_degauss, "disabled"),
             lambda _: not self._model.has_pbc,
         )
diff --git a/tests/configuration/test_advanced.py b/tests/configuration/test_advanced.py
index 0d888e95b..b42db6900 100644
--- a/tests/configuration/test_advanced.py
+++ b/tests/configuration/test_advanced.py
@@ -59,7 +59,7 @@ def test_advanced_convergence_settings(generate_structure_data):
     _ = ConvergenceConfigurationSettingsPanel(model=model)
 
     # Test structure-dependent convergence change
-    model.input_structure = generate_structure_data("silica")
+    model.structure_uuid = generate_structure_data("silica").uuid
 
     assert "num_atoms = 6" in model.help_message
 
@@ -106,7 +106,7 @@ def test_advanced_kpoints_mesh(generate_structure_data):
     _ = ConvergenceConfigurationSettingsPanel(model=model)
 
     structure = generate_structure_data(name="silicon")
-    model.input_structure = structure
+    model.structure_uuid = structure.uuid
 
     assert model.mesh_grid == "Mesh [14, 14, 14]"
 
@@ -122,7 +122,7 @@ def test_advanced_molecule_settings(generate_structure_data):
 
     # Create molecule
     structure = generate_structure_data(name="H2O", pbc=(False, False, False))
-    model.input_structure = structure
+    model.structure_uuid = structure.uuid
 
     # Confirm the value of kpoints_distance is fixed
     assert model.kpoints_distance == 100.0
@@ -175,7 +175,7 @@ def test_advanced_hubbard_settings(generate_structure_data):
     hubbard.render()
 
     structure = generate_structure_data(name="LiCoO2")
-    model.input_structure = structure
+    model.structure_uuid = structure.uuid
 
     # Activate Hubbard U widget
     model.is_active = True
@@ -244,7 +244,7 @@ def test_advanced_magnetic_settings(generate_structure_data):
     pseudo_family = get_pseudo_family_by_label("SSSP/1.3/PBE/efficiency")
 
     structure = generate_structure_data(name="LiCoO2")
-    model.input_structure = structure
+    model.structure_uuid = structure.uuid
     model.spin_type = "collinear"
     model.dictionary = {
         kind.name: pseudo_family.get_pseudo(kind.symbol).uuid
@@ -282,8 +282,9 @@ def test_advanced_magnetic_settings(generate_structure_data):
         symbols="O",
         name="O2",
     )
+    structure.store()
 
-    model.input_structure = structure
+    model.structure_uuid = structure.uuid
     model.dictionary = {
         kind.name: pseudo_family.get_pseudo(kind.symbol).uuid
         for kind in structure.kinds
diff --git a/tests/conftest.py b/tests/conftest.py
index 931bad0a8..a93a9f649 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -82,7 +82,7 @@ def fixture_localhost(aiida_localhost):
 def generate_structure_data():
     """generate a `StructureData` object."""
 
-    def _generate_structure_data(name="silicon", pbc=(True, True, True)):
+    def _generate_structure_data(name="silicon", pbc=(True, True, True), store=True):
         if name == "silicon":
             structure = orm.StructureData(
                 cell=[
@@ -157,6 +157,9 @@ def _generate_structure_data(name="silicon", pbc=(True, True, True)):
 
         structure.pbc = pbc
 
+        if store:
+            structure.store()
+
         return structure
 
     return _generate_structure_data
@@ -420,7 +423,7 @@ def _submit_app_generator(
         initial_magnetic_moments=0.0,
         electron_maxstep=80,
     ):
-        app.structure_model.input_structure = generate_structure_data()
+        app.structure_model.structure_uuid = generate_structure_data().uuid
         app.structure_model.confirm()
 
         parameters = {
@@ -472,7 +475,7 @@ def _submit_app_generator(
 @pytest.fixture
 def app_to_submit(app: WizardApp, generate_structure_data):
     # Step 1: select structure from example
-    app.structure_model.input_structure = generate_structure_data()
+    app.structure_model.structure_uuid = generate_structure_data().uuid
     app.structure_model.confirm()
     # Step 2: configure calculation
     # TODO do we need to include bands and pdos here?
@@ -711,14 +714,8 @@ def _generate_qeapp_workchain(
             structure = generate_structure_data()
         else:
             structure.store()
-            # TODO is this necessary?
-            # aiida_database_wrapper = app.structure_step.manager.children[0].children[2]  # type: ignore
-            # aiida_database_wrapper.render()
-            # aiida_database = aiida_database_wrapper.children[0]  # type: ignore
-            # aiida_database.search()
-            # aiida_database.results.value = structure
-
-        app.structure_model.input_structure = structure
+
+        app.structure_model.structure_uuid = structure.uuid
         app.structure_model.confirm()
 
         # step 2 configure
diff --git a/tests/test_app.py b/tests/test_app.py
index 843bf37ba..434b0619f 100644
--- a/tests/test_app.py
+++ b/tests/test_app.py
@@ -28,8 +28,8 @@ def test_selecting_new_structure_unconfirms_model(generate_structure_data):
     from aiidalab_qe.app.structure.model import StructureStepModel
 
     model = StructureStepModel()
-    model.input_structure = generate_structure_data()
+    model.structure_uuid = generate_structure_data().uuid
     assert model.has_structure
     model.confirm()
-    model.input_structure = generate_structure_data()
+    model.structure_uuid = generate_structure_data().uuid
     assert not model.confirmed
diff --git a/tests/test_pseudo.py b/tests/test_pseudo.py
index 4d18ae1df..47f42e315 100644
--- a/tests/test_pseudo.py
+++ b/tests/test_pseudo.py
@@ -154,7 +154,7 @@ def test_pseudos_settings(generate_structure_data, generate_upf_data):
     pseudos = PseudosConfigurationSettingsPanel(model=model)
 
     silicon = generate_structure_data("silicon")
-    model.input_structure = silicon
+    model.structure_uuid = silicon.uuid
 
     # Test the default family
     assert model.family == f"SSSP/{SSSP_VERSION}/PBEsol/efficiency"
@@ -184,7 +184,7 @@ def test_pseudos_settings(generate_structure_data, generate_upf_data):
 
     # Test that changing the structure triggers a reset
     silica = generate_structure_data("silica")
-    model.input_structure = silica
+    model.structure_uuid = silica.uuid
     assert model.family == f"SSSP/{SSSP_VERSION}/PBEsol/efficiency"
     assert "Si" in model.dictionary.keys()
     assert "O" in model.dictionary.keys()
@@ -355,7 +355,7 @@ def test_missing_pseudos(generate_structure_data):
     """Test that the model handles missing pseudos correctly."""
     model = PseudosConfigurationSettingsModel()
     _ = PseudosConfigurationSettingsPanel(model=model)
-    model.input_structure = generate_structure_data("CeO")
+    model.structure_uuid = generate_structure_data("CeO").uuid
     model.functional = "PBEsol"
     model.library = "PseudoDojo standard (SR)"
     assert model.family == "PseudoDojo/0.4/PBEsol/SR/standard/upf"
@@ -369,7 +369,7 @@ def test_functional_mismatch_blocker(generate_structure_data):
     """Test blocker for inconsistent functional across selected pseudopotentials."""
     model = PseudosConfigurationSettingsModel()
     _ = PseudosConfigurationSettingsPanel(model=model)
-    model.input_structure = generate_structure_data("silica")
+    model.structure_uuid = generate_structure_data("silica").uuid
     model.functionals = ["PBE", "PBEsol"]
     assert len(model.blockers) == 1
     assert "must have the same exchange-correlation" in model.blockers[0]
@@ -381,7 +381,7 @@ def test_relativistic_mismatch_blocker(generate_structure_data):
     """
     model = PseudosConfigurationSettingsModel()
     _ = PseudosConfigurationSettingsPanel(model=model)
-    model.input_structure = generate_structure_data("silica")
+    model.structure_uuid = generate_structure_data("silica").uuid
     model.spin_orbit = "soc"
     model.family = "SSSP/1.3/PBEsol/efficiency"
     assert len(model.blockers) == 1
diff --git a/tests/test_result.py b/tests/test_result.py
index 5757a882a..8f7a09b52 100644
--- a/tests/test_result.py
+++ b/tests/test_result.py
@@ -150,12 +150,11 @@ def test_table_data(model):
 
     wc = generate_qeapp_workchain(relax_type="none")
     model.process_uuid = wc.node.uuid
-    node = model.fetch_process_node()
     assert "Si<sub>2</sub>" in model.header
     assert "Initial" in model.sub_header
     assert "properties" in model.source  # inputs
-    assert model.structure.pk == node.inputs.structure.pk
-    assert str(node.inputs.structure.pk) in model.info
+    assert model.structure.pk == model.inputs.structure.pk
+    assert str(model.inputs.structure.pk) in model.info
     test_table_data(model)
 
     panel.render()
@@ -163,7 +162,6 @@ def test_table_data(model):
 
     wc = generate_qeapp_workchain(relax_type="positions_cell")
     model.process_uuid = wc.node.uuid
-    node = model.fetch_process_node()
     assert "Initial" in model.sub_header
     assert panel.view_toggle_button.layout.display == "block"
     assert panel.view_toggle_button.description == "View relaxed"
@@ -171,6 +169,6 @@ def test_table_data(model):
     assert panel.view_toggle_button.description == "View initial"
     assert "Relaxed" in model.sub_header
     assert "properties" not in model.source  # outputs
-    assert model.structure.pk == node.outputs.structure.pk
-    assert str(node.outputs.structure.pk) in model.info
+    assert model.structure.pk == model.outputs.structure.pk
+    assert str(model.outputs.structure.pk) in model.info
     test_table_data(model)
diff --git a/tests/test_status.py b/tests/test_status.py
index 613356597..b45cd5d79 100644
--- a/tests/test_status.py
+++ b/tests/test_status.py
@@ -237,7 +237,7 @@ def update_monitor():
             def delayed_add_branches_recursive(
                 node: orm.ProcessNode | None = None,
             ):
-                node = node or self.tree.trunk.node
+                node = node or self.tree.trunk.process
                 for child in sorted(node.called, key=lambda child: child.ctime):
                     if isinstance(child, orm.CalcFunctionNode):
                         continue
@@ -306,8 +306,8 @@ def test_calcjob_node_link(self):
         trunk = self.tree.trunk
         trunk.expand(recursive=True)
         self.calcjob_node.label.click()
-        assert self.panel.process_tree.value == self.calcjob_node.uuid
-        assert self.panel.process_tree._tree.nodes == (self.calcjob_node.node,)
+        assert self.panel.process_tree.value == self.calcjob_node.process_uuid
+        assert self.panel.process_tree._tree.nodes == (self.calcjob_node.process,)
         # TODO understand why the following does not trigger automatically as in the app
         # TODO understand why the following triggers a thread
         # self.panel.process_tree.set_trait("selected_nodes", [self.calcjob_node.node])
diff --git a/tests/test_submit_qe_workchain.py b/tests/test_submit_qe_workchain.py
index f6ccd1082..26592b0ab 100644
--- a/tests/test_submit_qe_workchain.py
+++ b/tests/test_submit_qe_workchain.py
@@ -167,7 +167,7 @@ def test_warning_messages(
 
     # now we use a large structure, so we should have the Warning-1 (and 2 if not on localhost)
     structure = generate_structure_data("H2O-larger")
-    submit_model.input_structure = structure
+    submit_model.structure_uuid = structure.uuid
     pw_code.num_cpus = 1
     global_model.check_resources()
     num_sites = len(structure.sites)