diff --git a/docs/schema/coremeta4cat.yaml b/docs/schema/coremeta4cat.yaml
index 3f6072e5c..423f40983 100644
--- a/docs/schema/coremeta4cat.yaml
+++ b/docs/schema/coremeta4cat.yaml
@@ -715,9 +715,10 @@ slots:
     mappings:
     - VOC4CAT:0000187
     slot_uri: VOC4CAT:0000187
-    owner: ThermalSynthesisMixin
+    owner: Characterization
     domain_of:
     - ThermalSynthesisMixin
+    - Characterization
     range: string
     multivalued: true
   flow_rate:
@@ -3716,6 +3717,27 @@ slots:
     domain_of:
     - FluidizedBedReactor
     range: string
+  product_identification_method:
+    name: product_identification_method
+    definition_uri: https://w3id.org/nfdi4cat/coremeta4cat/product_identification_method
+    description: 'The analytical method used to identify and/or quantify reaction
+      products.
+
+      Should reference a CharacterizationTechnique instance (e.g. GCMS, HPLC_MS).
+
+      The abstract stub ProductIdentificationMethod is retained for backward compatibility.'
+    from_schema: https://w3id.org/nfdi4cat/coremeta4cat/reaction/
+    mappings:
+    - coremeta4cat:product_identification_method
+    slot_uri: coremeta4cat:product_identification_method
+    owner: Reaction
+    domain_of:
+    - Reaction
+    range: ProductIdentificationMethod
+    required: true
+    multivalued: true
+    inlined: true
+    inlined_as_list: true
   software_package:
     name: software_package
     definition_uri: https://w3id.org/nfdi4cat/coremeta4cat/software_package
@@ -6975,23 +6997,6 @@ slots:
       binds_value_of: id
       description: Restricts the allowable defined terms to the QUDT Unit vocabulary.
     recommended: true
-  product_identification_method:
-    name: product_identification_method
-    description: 'The analytical method used to identify and/or quantify reaction
-      products.
-
-      Should reference a CharacterizationTechnique instance (e.g. a GCMS or
-
-      HPLC_MS object from coremeta4cat_characterization_ap). The abstract stub
-
-      ProductIdentificationMethod is retained for backward compatibility.'
-    from_schema: https://w3id.org/nfdi4cat/coremeta4cat
-    slot_uri: coremeta4cat:product_identification_method
-    range: ProductIdentificationMethod
-    required: true
-    multivalued: true
-    inlined: true
-    inlined_as_list: true
   CatalysisDataset_rdf_type:
     name: CatalysisDataset_rdf_type
     definition_uri: https://w3id.org/nfdi-de/dcat-ap-plus/rdf_type
@@ -7442,6 +7447,7 @@ slots:
     inlined_as_list: true
   Reaction_product_identification_method:
     name: Reaction_product_identification_method
+    definition_uri: https://w3id.org/nfdi4cat/coremeta4cat/product_identification_method
     description: 'The analytical method used to identify and/or quantify reaction
       products.
 
@@ -7450,7 +7456,9 @@ slots:
       HPLC_MS object from coremeta4cat_characterization_ap). The abstract stub
 
       ProductIdentificationMethod is retained for backward compatibility.'
-    from_schema: https://w3id.org/nfdi4cat/coremeta4cat
+    from_schema: https://w3id.org/nfdi4cat/coremeta4cat/reaction/
+    mappings:
+    - coremeta4cat:product_identification_method
     is_a: product_identification_method
     domain: Reaction
     slot_uri: coremeta4cat:product_identification_method
@@ -7511,7 +7519,6 @@ slots:
     usage_slot_name: realized_plan
     range: SimulationMethod
     required: true
-    multivalued: true
     inlined: true
     inlined_as_list: true
   Simulation_carried_out_by:
@@ -12192,12 +12199,12 @@ classes:
     - ClassifierMixin_type
     - evaluated_activity
     - occurred_in
+    - Characterization_equipment
     - sample_state
     - sample_description
     - sample_preparation
     - sample_pretreatment
     - detector_type
-    - Characterization_equipment
     - Characterization_evaluated_entity
     - Characterization_realized_plan
     - Characterization_rdf_type
@@ -12935,10 +12942,10 @@ classes:
     - experiment_pressure
     - feed_composition_range
     - experiment_duration
+    - Reaction_product_identification_method
     - Reaction_rdf_type
     - Reaction_carried_out_by
     - Reaction_had_input_entity
-    - Reaction_product_identification_method
     slot_usage:
       rdf_type:
         name: rdf_type
@@ -12972,12 +12979,9 @@ classes:
           HPLC_MS object from coremeta4cat_characterization_ap). The abstract stub
 
           ProductIdentificationMethod is retained for backward compatibility.'
-        from_schema: https://w3id.org/nfdi4cat/coremeta4cat
-        slot_uri: coremeta4cat:product_identification_method
         range: ProductIdentificationMethod
         required: true
         multivalued: true
-        inlined: true
         inlined_as_list: true
     class_uri: SIO:010345
   ProductIdentificationMethod:
@@ -13001,7 +13005,6 @@ classes:
     mappings:
     - OBI:0000272
     is_a: Plan
-    abstract: true
     slots:
     - title
     - description
@@ -13300,8 +13303,6 @@ classes:
         description: The SimulationMethod (protocol) realized in this Simulation.
         range: SimulationMethod
         required: true
-        multivalued: true
-        inlined_as_list: true
       carried_out_by:
         name: carried_out_by
         description: The simulation software used, provided as a Software agent instance.
@@ -17078,5 +17079,5 @@ metamodel_version: 1.7.0
 source_file: coremeta4cat.yaml
 source_file_date: '2026-03-09T16:14:14'
 source_file_size: 6730
-generation_date: '2026-03-09T17:32:19'
+generation_date: '2026-03-10T08:36:44'
 
diff --git a/src/coremeta4cat/datamodel/coremeta4cat.py b/src/coremeta4cat/datamodel/coremeta4cat.py
index 6d12f2006..727f2acf7 100644
--- a/src/coremeta4cat/datamodel/coremeta4cat.py
+++ b/src/coremeta4cat/datamodel/coremeta4cat.py
@@ -1,5 +1,5 @@
 # Auto generated from coremeta4cat.yaml by pythongen.py version: 0.0.1
-# Generation date: 2026-03-09T17:19:45
+# Generation date: 2026-03-10T09:36:20
 # Schema: coremeta4cat-metadata
 #
 # id: https://w3id.org/nfdi4cat/coremeta4cat
@@ -1572,7 +1572,7 @@ class Simulation(DataGeneratingActivity):
     id: Union[str, SimulationId] = None
     software_package: Union[str, list[str]] = None
     calculated_property: Union[Union[dict, "CalculatedProperty"], list[Union[dict, "CalculatedProperty"]]] = None
-    realized_plan: Union[Union[dict, "SimulationMethod"], list[Union[dict, "SimulationMethod"]]] = None
+    realized_plan: Union[dict, "SimulationMethod"] = None
     rdf_type: Optional[Union[dict, "DefinedTerm"]] = None
     carried_out_by: Optional[Union[dict[Union[str, AgenticEntityId], Union[dict, AgenticEntity]], list[Union[dict, AgenticEntity]]]] = empty_dict()
     evaluated_entity: Optional[Union[dict[Union[str, EvaluatedEntityId], Union[dict, "EvaluatedEntity"]], list[Union[dict, "EvaluatedEntity"]]]] = empty_dict()
@@ -1597,9 +1597,8 @@ def __post_init__(self, *_: str, **kwargs: Any):
 
         if self._is_empty(self.realized_plan):
             self.MissingRequiredField("realized_plan")
-        if not isinstance(self.realized_plan, list):
-            self.realized_plan = [self.realized_plan] if self.realized_plan is not None else []
-        self.realized_plan = [v if isinstance(v, SimulationMethod) else SimulationMethod(**as_dict(v)) for v in self.realized_plan]
+        if not isinstance(self.realized_plan, SimulationMethod):
+            self.realized_plan = SimulationMethod(**as_dict(self.realized_plan))
 
         if self.rdf_type is not None and not isinstance(self.rdf_type, DefinedTerm):
             self.rdf_type = DefinedTerm(**as_dict(self.rdf_type))
@@ -2579,8 +2578,8 @@ class Reaction(EvaluatedActivity):
     id: Union[str, ReactionId] = None
     catalyst_quantity: Union[float, list[float]] = None
     reactant: Union[str, list[str]] = None
-    carried_out_by: Union[dict[Union[str, ReactorDesignTypeId], Union[dict, ReactorDesignType]], list[Union[dict, ReactorDesignType]]] = empty_dict()
     product_identification_method: Union[Union[dict, "ProductIdentificationMethod"], list[Union[dict, "ProductIdentificationMethod"]]] = None
+    carried_out_by: Union[dict[Union[str, ReactorDesignTypeId], Union[dict, ReactorDesignType]], list[Union[dict, ReactorDesignType]]] = empty_dict()
     catalyst_type: Optional[Union[str, list[str]]] = empty_list()
     reactor_temperature_range: Optional[Union[str, list[str]]] = empty_list()
     atmosphere: Optional[Union[str, list[str]]] = empty_list()
@@ -2608,16 +2607,16 @@ def __post_init__(self, *_: str, **kwargs: Any):
             self.reactant = [self.reactant] if self.reactant is not None else []
         self.reactant = [v if isinstance(v, str) else str(v) for v in self.reactant]
 
-        if self._is_empty(self.carried_out_by):
-            self.MissingRequiredField("carried_out_by")
-        self._normalize_inlined_as_list(slot_name="carried_out_by", slot_type=ReactorDesignType, key_name="id", keyed=True)
-
         if self._is_empty(self.product_identification_method):
             self.MissingRequiredField("product_identification_method")
         if not isinstance(self.product_identification_method, list):
             self.product_identification_method = [self.product_identification_method] if self.product_identification_method is not None else []
         self.product_identification_method = [v if isinstance(v, ProductIdentificationMethod) else ProductIdentificationMethod(**as_dict(v)) for v in self.product_identification_method]
 
+        if self._is_empty(self.carried_out_by):
+            self.MissingRequiredField("carried_out_by")
+        self._normalize_inlined_as_list(slot_name="carried_out_by", slot_type=ReactorDesignType, key_name="id", keyed=True)
+
         if not isinstance(self.catalyst_type, list):
             self.catalyst_type = [self.catalyst_type] if self.catalyst_type is not None else []
         self.catalyst_type = [v if isinstance(v, str) else str(v) for v in self.catalyst_type]
@@ -9221,6 +9220,9 @@ class slots:
 slots.bubble_size_distribution = Slot(uri=COREMETA4CAT.bubble_size_distribution, name="bubble_size_distribution", curie=COREMETA4CAT.curie('bubble_size_distribution'),
                    model_uri=COREMETA4CAT.bubble_size_distribution, domain=None, range=Optional[str])
 
+slots.product_identification_method = Slot(uri=COREMETA4CAT.product_identification_method, name="product_identification_method", curie=COREMETA4CAT.curie('product_identification_method'),
+                   model_uri=COREMETA4CAT.product_identification_method, domain=None, range=Union[Union[dict, ProductIdentificationMethod], list[Union[dict, ProductIdentificationMethod]]])
+
 slots.software_package = Slot(uri=COREMETA4CAT.software_package, name="software_package", curie=COREMETA4CAT.curie('software_package'),
                    model_uri=COREMETA4CAT.software_package, domain=None, range=Union[str, list[str]])
 
@@ -9854,9 +9856,6 @@ class slots:
 slots.quantitativeAttribute__unit = Slot(uri=QUDT.unit, name="quantitativeAttribute__unit", curie=QUDT.curie('unit'),
                    model_uri=COREMETA4CAT.quantitativeAttribute__unit, domain=None, range=Optional[Union[str, DefinedTermId]])
 
-slots.product_identification_method = Slot(uri=COREMETA4CAT.product_identification_method, name="product_identification_method", curie=COREMETA4CAT.curie('product_identification_method'),
-                   model_uri=COREMETA4CAT.product_identification_method, domain=None, range=Union[Union[dict, ProductIdentificationMethod], list[Union[dict, ProductIdentificationMethod]]])
-
 slots.CatalysisDataset_rdf_type = Slot(uri=RDF.type, name="CatalysisDataset_rdf_type", curie=RDF.curie('type'),
                    model_uri=COREMETA4CAT.CatalysisDataset_rdf_type, domain=CatalysisDataset, range=Optional[Union[dict, "DefinedTerm"]])
 
@@ -9921,7 +9920,7 @@ class slots:
                    model_uri=COREMETA4CAT.Simulation_rdf_type, domain=Simulation, range=Optional[Union[dict, "DefinedTerm"]])
 
 slots.Simulation_realized_plan = Slot(uri=PROV.used, name="Simulation_realized_plan", curie=PROV.curie('used'),
-                   model_uri=COREMETA4CAT.Simulation_realized_plan, domain=Simulation, range=Union[Union[dict, "SimulationMethod"], list[Union[dict, "SimulationMethod"]]])
+                   model_uri=COREMETA4CAT.Simulation_realized_plan, domain=Simulation, range=Union[dict, "SimulationMethod"])
 
 slots.Simulation_carried_out_by = Slot(uri=PROV.wasAssociatedWith, name="Simulation_carried_out_by", curie=PROV.curie('wasAssociatedWith'),
                    model_uri=COREMETA4CAT.Simulation_carried_out_by, domain=Simulation, range=Optional[Union[dict[Union[str, AgenticEntityId], Union[dict, AgenticEntity]], list[Union[dict, AgenticEntity]]]])
diff --git a/src/coremeta4cat/datamodel/coremeta4cat_pydantic.py b/src/coremeta4cat/datamodel/coremeta4cat_pydantic.py
index 7e2f9d091..acc5b0213 100644
--- a/src/coremeta4cat/datamodel/coremeta4cat_pydantic.py
+++ b/src/coremeta4cat/datamodel/coremeta4cat_pydantic.py
@@ -518,7 +518,8 @@ class ThermalSynthesisMixin(ConfiguredBaseModel):
     synthesis_duration: Optional[list[float]] = Field(default=[], description="""Total duration of the synthesis step.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'],
          'slot_uri': 'VOC4CAT:0000050',
          'unit': {'ucum_code': 'h'}} })
-    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'VOC4CAT:0000187'} })
+    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin', 'Characterization'],
+         'slot_uri': 'VOC4CAT:0000187'} })
     vessel_type: Optional[list[str]] = Field(default=[], description="""Type of reaction or synthesis vessel used.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'coremeta4cat:vessel_type'} })
     atmosphere: Optional[list[str]] = Field(default=[], description="""Gaseous environment or atmospheric conditions during a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin',
                        'MolecularSynthesis',
@@ -2045,6 +2046,8 @@ class Characterization(DataGeneratingActivity):
                                           'range': 'CharacterizationTechnique',
                                           'required': True}}})
 
+    equipment: list[str] = Field(default=..., description="""Instrument or equipment used for characterization.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin', 'Characterization'],
+         'slot_uri': 'VOC4CAT:0000187'} })
     sample_state: Optional[list[SampleStateEnum]] = Field(default=[], description="""Physical state of the sample during characterization.""", json_schema_extra = { "linkml_meta": {'domain_of': ['Characterization'], 'slot_uri': 'coremeta4cat:sample_state'} })
     sample_description: Optional[list[str]] = Field(default=[], description="""Free-text description of the sample used in this characterization.""", json_schema_extra = { "linkml_meta": {'domain_of': ['Characterization'],
          'slot_uri': 'coremeta4cat:sample_description'} })
@@ -5514,6 +5517,11 @@ class Reaction(EvaluatedActivity):
     experiment_duration: Optional[list[float]] = Field(default=[], description="""Total duration of the experiment or measurement run.""", json_schema_extra = { "linkml_meta": {'domain_of': ['PowderXRD', 'Reaction'],
          'slot_uri': 'AFR:0002455',
          'unit': {'ucum_code': 'h'}} })
+    product_identification_method: list[ProductIdentificationMethod] = Field(default=..., description="""The analytical method used to identify and/or quantify reaction products.
+Should reference a CharacterizationTechnique instance (e.g. a GCMS or
+HPLC_MS object from coremeta4cat_characterization_ap). The abstract stub
+ProductIdentificationMethod is retained for backward compatibility.""", json_schema_extra = { "linkml_meta": {'domain_of': ['Reaction'],
+         'slot_uri': 'coremeta4cat:product_identification_method'} })
     id: str = Field(default=..., description="""A slot to provide an URI for an entity within this schema.""", json_schema_extra = { "linkml_meta": {'domain_of': ['Activity',
                        'AgenticEntity',
                        'Dataset',
@@ -6566,7 +6574,8 @@ class Solvothermal(PreparationMethod, ThermalSynthesisMixin):
     synthesis_duration: Optional[list[float]] = Field(default=[], description="""Total duration of the synthesis step.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'],
          'slot_uri': 'VOC4CAT:0000050',
          'unit': {'ucum_code': 'h'}} })
-    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'VOC4CAT:0000187'} })
+    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin', 'Characterization'],
+         'slot_uri': 'VOC4CAT:0000187'} })
     vessel_type: Optional[list[str]] = Field(default=[], description="""Type of reaction or synthesis vessel used.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'coremeta4cat:vessel_type'} })
     atmosphere: Optional[list[str]] = Field(default=[], description="""Gaseous environment or atmospheric conditions during a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin',
                        'MolecularSynthesis',
@@ -6688,7 +6697,8 @@ class PlasmaAssisted(PreparationMethod, ThermalSynthesisMixin):
     synthesis_duration: Optional[list[float]] = Field(default=[], description="""Total duration of the synthesis step.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'],
          'slot_uri': 'VOC4CAT:0000050',
          'unit': {'ucum_code': 'h'}} })
-    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'VOC4CAT:0000187'} })
+    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin', 'Characterization'],
+         'slot_uri': 'VOC4CAT:0000187'} })
     vessel_type: Optional[list[str]] = Field(default=[], description="""Type of reaction or synthesis vessel used.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'coremeta4cat:vessel_type'} })
     atmosphere: Optional[list[str]] = Field(default=[], description="""Gaseous environment or atmospheric conditions during a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin',
                        'MolecularSynthesis',
@@ -6809,7 +6819,8 @@ class CombustionSynthesis(PreparationMethod, ThermalSynthesisMixin):
     synthesis_duration: Optional[list[float]] = Field(default=[], description="""Total duration of the synthesis step.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'],
          'slot_uri': 'VOC4CAT:0000050',
          'unit': {'ucum_code': 'h'}} })
-    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'VOC4CAT:0000187'} })
+    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin', 'Characterization'],
+         'slot_uri': 'VOC4CAT:0000187'} })
     vessel_type: Optional[list[str]] = Field(default=[], description="""Type of reaction or synthesis vessel used.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'coremeta4cat:vessel_type'} })
     atmosphere: Optional[list[str]] = Field(default=[], description="""Gaseous environment or atmospheric conditions during a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin',
                        'MolecularSynthesis',
@@ -7193,7 +7204,8 @@ class MicrowaveAssisted(PreparationMethod, ThermalSynthesisMixin):
     synthesis_duration: Optional[list[float]] = Field(default=[], description="""Total duration of the synthesis step.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'],
          'slot_uri': 'VOC4CAT:0000050',
          'unit': {'ucum_code': 'h'}} })
-    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'VOC4CAT:0000187'} })
+    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin', 'Characterization'],
+         'slot_uri': 'VOC4CAT:0000187'} })
     vessel_type: Optional[list[str]] = Field(default=[], description="""Type of reaction or synthesis vessel used.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'coremeta4cat:vessel_type'} })
     atmosphere: Optional[list[str]] = Field(default=[], description="""Gaseous environment or atmospheric conditions during a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin',
                        'MolecularSynthesis',
@@ -7580,7 +7592,8 @@ class MechanochemicalSynthesis(PreparationMethod, ThermalSynthesisMixin):
     synthesis_duration: Optional[list[float]] = Field(default=[], description="""Total duration of the synthesis step.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'],
          'slot_uri': 'VOC4CAT:0000050',
          'unit': {'ucum_code': 'h'}} })
-    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'VOC4CAT:0000187'} })
+    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin', 'Characterization'],
+         'slot_uri': 'VOC4CAT:0000187'} })
     vessel_type: Optional[list[str]] = Field(default=[], description="""Type of reaction or synthesis vessel used.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'coremeta4cat:vessel_type'} })
     atmosphere: Optional[list[str]] = Field(default=[], description="""Gaseous environment or atmospheric conditions during a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin',
                        'MolecularSynthesis',
@@ -7695,7 +7708,8 @@ class Sublimation(PreparationMethod, ThermalSynthesisMixin):
     synthesis_duration: Optional[list[float]] = Field(default=[], description="""Total duration of the synthesis step.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'],
          'slot_uri': 'VOC4CAT:0000050',
          'unit': {'ucum_code': 'h'}} })
-    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'VOC4CAT:0000187'} })
+    equipment: Optional[list[str]] = Field(default=[], description="""Equipment or instrument used in a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin', 'Characterization'],
+         'slot_uri': 'VOC4CAT:0000187'} })
     vessel_type: Optional[list[str]] = Field(default=[], description="""Type of reaction or synthesis vessel used.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin'], 'slot_uri': 'coremeta4cat:vessel_type'} })
     atmosphere: Optional[list[str]] = Field(default=[], description="""Gaseous environment or atmospheric conditions during a process.""", json_schema_extra = { "linkml_meta": {'domain_of': ['ThermalSynthesisMixin',
                        'MolecularSynthesis',
@@ -11485,8 +11499,7 @@ class ProductIdentificationMethod(Plan):
     CoreMeta4Cat monolith. It is a subclass of Plan (prov:Plan / OBI:0000272) so that
     it can participate in the realized_plan slot if needed.
     """
-    linkml_meta: ClassVar[LinkMLMeta] = LinkMLMeta({'abstract': True,
-         'class_uri': 'OBI:0000272',
+    linkml_meta: ClassVar[LinkMLMeta] = LinkMLMeta({'class_uri': 'OBI:0000272',
          'from_schema': 'https://w3id.org/nfdi4cat/coremeta4cat/reaction/'})
 
     title: Optional[str] = Field(default=None, description="""This slot is described in more detail within the class in which it is used.""", json_schema_extra = { "linkml_meta": {'domain_of': ['Activity',
@@ -18918,8 +18931,6 @@ class Simulation(DataGeneratingActivity):
                         'realized_plan': {'description': 'The SimulationMethod '
                                                          '(protocol) realized in this '
                                                          'Simulation.',
-                                          'inlined_as_list': True,
-                                          'multivalued': True,
                                           'name': 'realized_plan',
                                           'range': 'SimulationMethod',
                                           'required': True}}})
@@ -18938,7 +18949,7 @@ class Simulation(DataGeneratingActivity):
          'is_a': 'had_input_activity',
          'recommended': True,
          'slot_uri': 'prov:wasInformedBy'} })
-    realized_plan: list[SimulationMethod] = Field(default=..., description="""The SimulationMethod (protocol) realized in this Simulation.""", json_schema_extra = { "linkml_meta": {'domain_of': ['DataGeneratingActivity'],
+    realized_plan: SimulationMethod = Field(default=..., description="""The SimulationMethod (protocol) realized in this Simulation.""", json_schema_extra = { "linkml_meta": {'domain_of': ['DataGeneratingActivity'],
          'in_subset': ['domain_agnostic_core'],
          'slot_uri': 'prov:used'} })
     occurred_in: Optional[Surrounding] = Field(default=None, description="""The slot to specify the Surrounding in which an Activity took place.""", json_schema_extra = { "linkml_meta": {'domain_of': ['DataGeneratingActivity'],
diff --git a/src/coremeta4cat/schema/coremeta4cat_characterization_ap.yaml b/src/coremeta4cat/schema/coremeta4cat_characterization_ap.yaml
index 3c88f2586..e6a6f61f7 100644
--- a/src/coremeta4cat/schema/coremeta4cat_characterization_ap.yaml
+++ b/src/coremeta4cat/schema/coremeta4cat_characterization_ap.yaml
@@ -165,6 +165,7 @@ classes:
       following DCAT-AP-PLUS Pattern 3 — exactly as NMRSpectroscopy uses
       rdf_type: CHMO:0000613.
     slots:
+      - equipment
       - sample_state
       - sample_description
       - sample_preparation
diff --git a/src/coremeta4cat/schema/coremeta4cat_reaction_ap.yaml b/src/coremeta4cat/schema/coremeta4cat_reaction_ap.yaml
index c5f7e3fba..27b008c02 100644
--- a/src/coremeta4cat/schema/coremeta4cat_reaction_ap.yaml
+++ b/src/coremeta4cat/schema/coremeta4cat_reaction_ap.yaml
@@ -92,6 +92,7 @@ classes:
       - experiment_pressure
       - feed_composition_range
       - experiment_duration
+      - product_identification_method
     slot_usage:
       rdf_type:
         description: |-
@@ -129,7 +130,6 @@ classes:
   ProductIdentificationMethod:
     is_a: Plan
     class_uri: OBI:0000272
-    abstract: true
     description: |-
       Abstract Plan representing the method used to identify and quantify reaction
       products. In practice, users should reference a concrete CharacterizationTechnique
@@ -297,3 +297,14 @@ slots:
     description: Description or characterization of bubble size distribution in the fluidized bed.
     range: string
     slot_uri: coremeta4cat:bubble_size_distribution
+
+  product_identification_method:
+    description: |-
+      The analytical method used to identify and/or quantify reaction products.
+      Should reference a CharacterizationTechnique instance (e.g. GCMS, HPLC_MS).
+      The abstract stub ProductIdentificationMethod is retained for backward compatibility.
+    range: ProductIdentificationMethod
+    slot_uri: coremeta4cat:product_identification_method
+    required: true
+    multivalued: true
+    inlined_as_list: true
diff --git a/src/coremeta4cat/schema/coremeta4cat_simulation_ap.yaml b/src/coremeta4cat/schema/coremeta4cat_simulation_ap.yaml
index fda0b7655..47df02417 100644
--- a/src/coremeta4cat/schema/coremeta4cat_simulation_ap.yaml
+++ b/src/coremeta4cat/schema/coremeta4cat_simulation_ap.yaml
@@ -116,8 +116,6 @@ classes:
           The SimulationMethod (protocol) realized in this Simulation.
         range: SimulationMethod
         required: true
-        multivalued: true
-        inlined_as_list: true
       carried_out_by:
         description: |-
           The simulation software used, provided as a Software agent instance.
diff --git a/tests/data/valid/CatalysisDataset-001.yaml b/tests/data/valid/CatalysisDataset-001.yaml
new file mode 100644
index 000000000..e3eab3c34
--- /dev/null
+++ b/tests/data/valid/CatalysisDataset-001.yaml
@@ -0,0 +1,37 @@
+---
+# CatalysisDataset-001 -- Methanol synthesis over Cu/ZnO/Al2O3
+# Target class: CatalysisDataset
+#
+# This dataset covers Synthesis + Characterization + Reaction subprofiles.
+#
+# Naming note: user-preferred CatalysisDataset_Reac_Syn-001.yaml is incompatible
+# with test_data.py (stem.split("-")[0] gives invalid class name).
+# Using CatalysisDataset-001.yaml for test compatibility.
+# See SCHEMA_REVIEW.md: "File naming convention".
+#
+# JSON schema notes:
+# - title and description on CatalysisDataset must be arrays (DCAT multivalued).
+# - DataGeneratingActivity.title in JSON schema is also an array (or null).
+# - was_generated_by items must include at least title:[] to avoid a linkml_runtime
+#   loader bug where single-field JsonObj args cause DataGeneratingActivityId
+#   to receive a JsonObj instead of a string.
+
+id: "coremeta4cat:DS_001_MeOH_synthesis_CuZnO"
+title:
+  - "Methanol synthesis over Cu/ZnO/Al2O3: synthesis and catalytic performance dataset"
+description:
+  - "Dataset covering preparation of Cu/ZnO/Al2O3 methanol synthesis catalyst by incipient wetness impregnation and catalytic performance in CO2 hydrogenation at 50 bar, 200-300 deg C."
+was_generated_by:
+  - id: "coremeta4cat:SYNTH_001_Pt_Al2O3"
+    title:
+      - "incipient wetness impregnation of Cu/ZnO/Al2O3"
+  - id: "coremeta4cat:CHAR_001_BET_CuZnO_Al2O3"
+    title:
+      - "BET surface area measurement of Cu/ZnO/Al2O3"
+  - id: "coremeta4cat:CHAR_002_XRD_CuZnO_Al2O3"
+    title:
+      - "Powder XRD measurement of Cu/ZnO/Al2O3"
+is_about_entity:
+  - id: "coremeta4cat:CAT_001_CuZnO_Al2O3"
+    title: "Cu/ZnO/Al2O3 methanol synthesis catalyst"
+    description: "63 wt% CuO, 24 wt% ZnO, 13 wt% Al2O3 (calcined precursor)"
diff --git a/tests/data/valid/CatalysisDataset-002.yaml b/tests/data/valid/CatalysisDataset-002.yaml
new file mode 100644
index 000000000..1913ba9d6
--- /dev/null
+++ b/tests/data/valid/CatalysisDataset-002.yaml
@@ -0,0 +1,41 @@
+---
+# CatalysisDataset-002 -- NiO/CeO2 dry methane reforming catalyst study
+# Target class: CatalysisDataset
+#
+# Comprehensive dataset linking synthesis, characterization, reaction, and simulation
+# activities for the NiO/CeO2 DRM catalyst system (files -002 series).
+#
+# JSON schema notes (same as CatalysisDataset-001):
+# - title and description must be arrays (DCAT multivalued).
+# - was_generated_by items must include at least title:[] to avoid linkml_runtime
+#   JsonObj loader bug (single-field objects passed as positional arg).
+# - is_about_entity items inlined with title and description.
+
+id: "coremeta4cat:DS_002_DRM_NiO_CeO2"
+title:
+  - "NiO/CeO2 dry methane reforming catalyst: co-precipitation synthesis, multi-technique characterization, catalytic performance, and computational interface study"
+description:
+  - "Dataset covering the full lifecycle of a 15 wt% NiO/CeO2 dry reforming catalyst: (1) co-precipitation synthesis with precipitation parameters and calcination protocol; (2) XPS surface composition and oxidation state analysis; (3) H2-TPR reducibility profiling; (4) catalytic performance in CH4+CO2 dry reforming at 600-800 deg C over 20 h; (5) ReaxFF molecular dynamics of the Ni/CeO2(111) interface at 800 deg C to rationalise metal-support interaction."
+was_generated_by:
+  - id: "coremeta4cat:SYNTH_002_NiO_CeO2"
+    title:
+      - "co-precipitation synthesis of 15 wt% NiO/CeO2"
+  - id: "coremeta4cat:CHAR_003_XPS_NiO_CeO2"
+    title:
+      - "XPS surface analysis of NiO/CeO2 (Ni 2p, Ce 3d, O 1s)"
+  - id: "coremeta4cat:CHAR_004_TPR_NiO_CeO2"
+    title:
+      - "H2-TPR reducibility measurement of NiO/CeO2"
+  - id: "coremeta4cat:REAC_002_DRM_NiCeO2"
+    title:
+      - "dry methane reforming catalytic activity test (600-800 deg C, 20 h)"
+  - id: "coremeta4cat:SIM_002_MD_Ni_CeO2_111"
+    title:
+      - "ReaxFF MD simulation of Ni13 cluster on CeO2(111) at 800 deg C"
+is_about_entity:
+  - id: "coremeta4cat:CAT_002_NiO_CeO2"
+    title: "NiO/CeO2 dry reforming catalyst"
+    description: "15 wt% NiO on CeO2 support, co-precipitated at pH 8.5, calcined 500 deg C / 4 h, active phase Ni0 formed by in situ reduction"
+  - id: "coremeta4cat:SLAB_002_CeO2_111_Ni13"
+    title: "Ni13/CeO2(111) computational model"
+    description: "13-atom cuboctahedral Ni cluster on 6-layer CeO2(111) p(4x4) periodic slab; ReaxFF MD model representing Ni/CeO2 metal-support interface"
diff --git a/tests/data/valid/Characterization-001.yaml b/tests/data/valid/Characterization-001.yaml
new file mode 100644
index 000000000..59d1ac446
--- /dev/null
+++ b/tests/data/valid/Characterization-001.yaml
@@ -0,0 +1,19 @@
+---
+# Characterization-001 -- BET surface area measurement of Cu/ZnO/Al2O3 catalyst
+# Target class: Characterization
+#
+# NOTE: realized_plan range is CharacterizationTechnique (abstract).
+# The generated Python loader instantiates the abstract CharacterizationTechnique;
+# concrete BET subclass fields are silently ignored.
+# Technique identity is expressed via title/description on realized_plan.
+
+id: "coremeta4cat:CHAR_001_BET_CuZnO_Al2O3"
+equipment:
+  - "Micromeritics ASAP 2020 surface area and porosimetry analyzer"
+evaluated_entity:
+  - id: "coremeta4cat:CAT_001_CuZnO_Al2O3"
+    title: "Cu/ZnO/Al2O3 methanol synthesis catalyst"
+    description: "63 wt% CuO, 24 wt% ZnO, 13 wt% Al2O3 (calcined precursor)"
+realized_plan:
+  title: "BET surface area measurement"
+  description: "N2 physisorption at 77 K, degassing at 300 deg C for 3 h under vacuum prior to measurement"
diff --git a/tests/data/valid/Characterization-002.yaml b/tests/data/valid/Characterization-002.yaml
new file mode 100644
index 000000000..59874512c
--- /dev/null
+++ b/tests/data/valid/Characterization-002.yaml
@@ -0,0 +1,19 @@
+---
+# Characterization-002 -- Powder XRD measurement of Cu/ZnO/Al2O3 catalyst
+# Target class: Characterization
+#
+# NOTE: realized_plan range is CharacterizationTechnique (abstract).
+# The generated Python loader instantiates the abstract CharacterizationTechnique;
+# concrete PowderXRD subclass fields are silently ignored.
+# Technique identity is expressed via title/description on realized_plan.
+
+id: "coremeta4cat:CHAR_002_XRD_CuZnO_Al2O3"
+equipment:
+  - "Bruker D8 Advance diffractometer with Cu K-alpha radiation (1.5406 Ang)"
+evaluated_entity:
+  - id: "coremeta4cat:CAT_001_CuZnO_Al2O3"
+    title: "Cu/ZnO/Al2O3 methanol synthesis catalyst"
+    description: "63 wt% CuO, 24 wt% ZnO, 13 wt% Al2O3 (calcined precursor)"
+realized_plan:
+  title: "powder X-ray diffraction"
+  description: "Cu K-alpha, 2theta range 5 to 80 deg, step size 0.02 deg, scan rate 1 deg/min, Rietveld refinement for phase quantification"
diff --git a/tests/data/valid/Characterization-003.yaml b/tests/data/valid/Characterization-003.yaml
new file mode 100644
index 000000000..51a68748f
--- /dev/null
+++ b/tests/data/valid/Characterization-003.yaml
@@ -0,0 +1,36 @@
+---
+# Characterization-003 -- XPS surface analysis of NiO/CeO2 catalyst
+# Target class: Characterization
+#
+# Technique: XPS (XRaySourceMixin + EnergyRangeMixin + technique-specific slots).
+# realized_plan range is CharacterizationTechnique (abstract) -- Python loader
+# instantiates abstract class; XPS-specific parameters encoded in description.
+#
+# Demonstrates:
+#   - Full Characterization-level slots: sample_state, sample_description,
+#     sample_preparation, sample_pretreatment, detector_type
+#   - Multiple equipment items (instrument + X-ray source specification)
+#   - Rich realized_plan description encoding survey + HR scan parameters,
+#     pass energy, spot size, charge compensation, binding energy calibration
+
+id: "coremeta4cat:CHAR_003_XPS_NiO_CeO2"
+equipment:
+  - "Thermo Scientific K-Alpha+ XPS spectrometer"
+  - "Al K-alpha monochromatic X-ray source (1486.6 eV, 72 W)"
+sample_state:
+  - "powder"
+sample_description:
+  - "NiO/CeO2 co-precipitated catalyst (SYNTH_002), calcined at 500 deg C, as-prepared (non-reduced), ca. 10 mg pressed into indium foil"
+sample_preparation:
+  - "lightly pressed into indium foil to obtain flat surface; mounted on sample stub with copper tape; no Ar+ sputtering performed"
+sample_pretreatment:
+  - "outgassed in XPS load-lock chamber at < 1e-7 mbar for 12 h before transfer to analysis chamber (< 5e-9 mbar)"
+detector_type:
+  - "128-channel 2D delay-line detector (DLD)"
+evaluated_entity:
+  - id: "coremeta4cat:CAT_002_NiO_CeO2"
+    title: "NiO/CeO2 dry reforming catalyst (calcined)"
+    description: "15 wt% NiO on CeO2 support, calcined at 500 deg C"
+realized_plan:
+  title: "X-ray photoelectron spectroscopy (XPS)"
+  description: "monochromatic Al K-alpha (1486.6 eV); base pressure 5e-9 mbar; survey scan: 0-1350 eV, 1.0 eV step, 50 ms dwell, 3 scans, pass energy 200 eV; high-resolution regions: Ni 2p3/2 (845-895 eV), Ce 3d (875-935 eV), O 1s (525-540 eV), C 1s (280-295 eV); step size 0.1 eV, 20 scans each, pass energy 50 eV; spot size 400 um; lens mode: large area XL; charge compensation: dual-beam flood gun (1 eV electrons + 10 eV Ar+); binding energy scale calibrated to C 1s adventitious carbon at 284.8 eV; Shirley background subtraction; peak fitting: Voigt profiles (CasaXPS v2.3.25); atomic concentrations from Scofield sensitivity factors corrected for transmission function"
diff --git a/tests/data/valid/Characterization-004.yaml b/tests/data/valid/Characterization-004.yaml
new file mode 100644
index 000000000..2f2e81411
--- /dev/null
+++ b/tests/data/valid/Characterization-004.yaml
@@ -0,0 +1,30 @@
+---
+# Characterization-004 -- H2 temperature-programmed reduction (H2-TPR) of NiO/CeO2
+# Target class: Characterization
+#
+# Technique: TPR (TemperatureProgramMixin: minimum_temperature, maximum_temperature,
+#             heating_rate, heating_procedure slots in realized_plan description).
+# realized_plan range is CharacterizationTechnique (abstract) -- TPR params in description.
+#
+# Demonstrates:
+#   - TPR characterization with full temperature programme description
+#   - sample_description, sample_pretreatment (oxidative pre-treatment before reduction)
+#   - detector_type (TCD)
+#   - Two evaluated_entity items (fresh catalyst + spent catalyst comparison)
+
+id: "coremeta4cat:CHAR_004_TPR_NiO_CeO2"
+equipment:
+  - "Micromeritics AutoChem II 2920 chemisorption analyzer"
+sample_description:
+  - "NiO/CeO2 calcined at 500 deg C; 50 mg packed in quartz U-tube reactor (4 mm ID); quartz wool plugs above and below bed"
+sample_pretreatment:
+  - "oxidative pretreatment: 10 vol% O2/Ar (50 mL/min) at 300 deg C for 30 min; cool to 50 deg C under Ar purge"
+detector_type:
+  - "thermal conductivity detector (TCD), Ar carrier gas reference channel"
+evaluated_entity:
+  - id: "coremeta4cat:CAT_002_NiO_CeO2"
+    title: "NiO/CeO2 dry reforming catalyst (calcined)"
+    description: "15 wt% NiO on CeO2, calcined at 500 deg C / 4 h"
+realized_plan:
+  title: "H2 temperature-programmed reduction (H2-TPR)"
+  description: "reducing gas: 5 vol% H2/Ar, total flow 50 mL/min (calibrated Brooks MFC); temperature programme: 50 deg C to 900 deg C at 10 deg C/min; isothermal hold: 30 min at 900 deg C; H2O trap: molecular sieve 3A between reactor outlet and TCD to prevent TCD signal interference; baseline: Ar flow for 30 min at 50 deg C before switching to H2/Ar; H2 consumption quantified by integration of TCD signal, calibrated against CuO reference standard (99.9%, 10 mg, single reduction peak at 310 deg C); NiO reduction: expected peaks at 280-350 deg C (NiO weakly interacting with CeO2) and 400-600 deg C (NiO strongly interacting); CeO2 surface reduction: 600-900 deg C"
diff --git a/tests/data/valid/Reaction-001.yaml b/tests/data/valid/Reaction-001.yaml
new file mode 100644
index 000000000..167bbedd9
--- /dev/null
+++ b/tests/data/valid/Reaction-001.yaml
@@ -0,0 +1,42 @@
+---
+# Reaction-001 -- CO2 hydrogenation to methanol over Cu/ZnO/Al2O3 in fixed-bed reactor
+# Target class: Reaction
+#
+# SCHEMA ERROR (product_identification_method): The slot range is abstract
+# ProductIdentificationMethod (a Plan stub with no concrete subclasses).
+# The schema description says to reference a CharacterizationTechnique, but
+# CharacterizationTechnique is NOT a subclass of ProductIdentificationMethod.
+# As a workaround, title/description are provided on the abstract stub;
+# the generated Python loader instantiates ProductIdentificationMethod directly.
+# See SCHEMA_REVIEW.md for the proposed fix.
+#
+# NOTE (carried_out_by): keyed inline list; each item needs an id.
+# The loader instantiates the abstract ReactorDesignType (not FixedBedReactor).
+
+id: "coremeta4cat:REAC_001_CO2_hydrogenation"
+catalyst_quantity:
+  - 0.5
+reactant:
+  - "CO2 (99.998% purity, 20 vol% in H2)"
+  - "H2 (99.999% purity)"
+catalyst_type:
+  - "heterogeneous, supported metal oxide"
+reactor_temperature_range:
+  - "200-300 deg C"
+experiment_pressure:
+  - 50.0
+atmosphere:
+  - "H2/CO2 = 3:1 (molar), GHSV = 10000 mL/(g*h)"
+feed_composition_range:
+  - "H2/CO2 = 3:1, CO2 concentration 20 vol%"
+carried_out_by:
+  - id: "coremeta4cat:REACT_001_FixedBed"
+    title: "stainless steel fixed-bed plug-flow reactor"
+    description: "10 mm inner diameter, 30 cm length, 0.5 g catalyst diluted with SiC"
+had_input_entity:
+  - id: "coremeta4cat:FEED_001_CO2_H2"
+    title: "CO2/H2 feed gas mixture"
+    description: "H2/CO2 molar ratio 3:1, total flow 100 mL/min"
+product_identification_method:
+  - title: "online gas chromatography"
+    description: "GC (Agilent 7890B) with TCD and FID detectors; columns: Molecular Sieve 5A and Poraplot Q; products: MeOH, CO, CH4, H2O quantified"
diff --git a/tests/data/valid/Reaction-002.yaml b/tests/data/valid/Reaction-002.yaml
new file mode 100644
index 000000000..6e8ed5061
--- /dev/null
+++ b/tests/data/valid/Reaction-002.yaml
@@ -0,0 +1,52 @@
+---
+# Reaction-002 -- Dry methane reforming (DRM) over Ni/CeO2 in fixed-bed reactor
+# Target class: Reaction
+#
+# NOTE (carried_out_by): range is ReactorDesignType (abstract: true) -> dangling $ref.
+# Loader instantiates abstract ReactorDesignType. Each item needs an id.
+# NOTE (product_identification_method): same abstract stub limitation as Reaction-001.
+#
+# Demonstrates:
+#   - Two reactants (CH4 + CO2) with separate had_input_entity feed descriptions
+#   - experiment_duration (20 h stability test)
+#   - feed_composition_range (two entries: stoichiometric + CO2-rich conditions)
+#   - Detailed product_identification_method (online GC with two columns)
+#   - FixedBedReactor with detailed description (quartz tube, dilution, thermocouple)
+
+id: "coremeta4cat:REAC_002_DRM_NiCeO2"
+catalyst_quantity:
+  - 0.2
+catalyst_type:
+  - "heterogeneous, supported metal (Ni0 after in situ reduction of NiO/CeO2)"
+reactant:
+  - "CH4 (99.995% purity, Linde)"
+  - "CO2 (99.998% purity, Linde)"
+  - "N2 balance (99.999% purity, internal standard for GC quantification)"
+reactor_temperature_range:
+  - "600-800 deg C"
+experiment_pressure:
+  - 1.0
+atmosphere:
+  - "CH4/CO2/N2 = 45:45:10 vol%, total flow 100 mL/min (STP), GHSV = 30000 mL/(g*h)"
+feed_composition_range:
+  - "stoichiometric DRM: CH4/CO2 = 1:1 (molar)"
+  - "CO2-rich condition: CH4/CO2 = 1:1.5 to suppress carbon deposition"
+experiment_duration:
+  - 20.0
+carried_out_by:
+  - id: "coremeta4cat:REACT_003_FixedBed_DRM"
+    title: "quartz fixed-bed plug-flow reactor (DRM)"
+    description: "quartz tube reactor, 8 mm inner diameter, 30 cm length; catalyst bed: 200 mg NiO/CeO2 (250-500 um sieve fraction) diluted 1:2 (mass) with inert SiC chips (500 um); thermocouple inserted into catalyst bed centre; backpressure regulator at outlet (1 bar); reactor surrounded by ceramic-fibre furnace with PID temperature controller; mass flow controllers (Brooks SLA5850) for CH4, CO2, N2"
+had_input_entity:
+  - id: "coremeta4cat:FEED_004_CH4_DRM"
+    title: "methane feed (99.995%, Linde)"
+    description: "CH4 flow: 45 mL/min (STP); calibrated Brooks SLA5850 MFC"
+  - id: "coremeta4cat:FEED_005_CO2_DRM"
+    title: "CO2 feed (99.998%, Linde)"
+    description: "CO2 flow: 45 mL/min (STP); calibrated Brooks SLA5850 MFC"
+  - id: "coremeta4cat:FEED_006_N2_standard"
+    title: "N2 internal standard (99.999%, Linde)"
+    description: "N2 flow: 10 mL/min (STP); used as internal standard for GC molar balance"
+product_identification_method:
+  - title: "online dual-column gas chromatography (TCD)"
+    description: "Shimadzu GC-2014 with TCD detector (Ar carrier gas); column 1: HayeSep D (2 m x 1/8 in) for CO2, CH4 separation; column 2: Molecular Sieve 5A (2 m x 1/8 in) for CO, H2, N2, CH4 separation; 10-port Valco valve for column switching; oven temperature: 50 deg C isothermal; TCD temperature: 250 deg C; injection: automated gas sampling valve, 1 mL loop; analysis cycle: 10 min; calibration: certified gas standard (Air Liquide CRYSTAL mixture: H2 5%, CO 5%, CH4 5%, CO2 10%, N2 balance); CH4 conversion, CO2 conversion, H2/CO ratio, and carbon balance calculated from N2-normalised molar flows"
diff --git a/tests/data/valid/Simulation-001.yaml b/tests/data/valid/Simulation-001.yaml
new file mode 100644
index 000000000..f246e9d07
--- /dev/null
+++ b/tests/data/valid/Simulation-001.yaml
@@ -0,0 +1,33 @@
+---
+# Simulation-001 -- DFT calculation of CO adsorption on Cu(111) surface
+# Target class: Simulation
+#
+# NOTE: realized_plan range is SimulationMethod (abstract).
+# The generated Python loader always instantiates abstract SimulationMethod;
+# concrete DFT subclass fields (exchange_correlation_functional, energy_cutoff, …)
+# are silently ignored at load time.
+#
+# NOTE: calculated_property range is CalculatedProperty (abstract).
+# Each item MUST include "value" (required by QualitativeAttribute base class).
+# Concrete subclass fields are silently ignored at load time.
+#
+# Both realized_plan and calculated_property are lists (multivalued).
+
+id: "coremeta4cat:SIM_001_DFT_Cu111_CO_ads"
+software_package:
+  - "VASP 6.3.0"
+  - "VESTA 3.5.8 (structure visualization)"
+evaluated_entity:
+  - id: "coremeta4cat:SLAB_001_Cu111"
+    title: "Cu(111) surface slab model"
+    description: "4-layer Cu(111) p(3x3) slab, bottom 2 layers fixed, 15 Ang vacuum"
+realized_plan:
+  title: "periodic plane-wave DFT"
+  description: "PBE functional, PAW pseudopotentials, 400 eV cutoff, 4x4x1 Monkhorst-Pack k-mesh, D3 dispersion correction, spin-unpolarized"
+calculated_property:
+  - value: "-0.67 eV"
+    description: "CO adsorption energy on hollow fcc site of Cu(111) relative to gas-phase CO"
+  - value: "1.157 Ang"
+    description: "C-O bond length of adsorbed CO"
+  - value: "2.312 Ang"
+    description: "Cu-C bond length at hollow adsorption site"
diff --git a/tests/data/valid/Simulation-002.yaml b/tests/data/valid/Simulation-002.yaml
new file mode 100644
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+---
+# Simulation-002 -- ReaxFF molecular dynamics of Ni cluster on CeO2(111) surface
+# Target class: Simulation
+#
+# NOTE: realized_plan range is SimulationMethod (abstract).
+# Python loader always instantiates abstract SimulationMethod; MolecularDynamics
+# subclass fields (force_field, simulation_timestep, ensemble_type, etc.)
+# are silently ignored at load time. All MD parameters encoded in description.
+#
+# NOTE: calculated_property range is CalculatedProperty (abstract).
+# Each item MUST include "value" (required by QualitativeAttribute base class).
+# Concrete subclass fields are silently ignored at load time.
+#
+# Demonstrates:
+#   - MolecularDynamics SimulationMethod (contrast with DFT in Simulation-001)
+#   - Four calculated_property entries with diverse value types
+#   - Two software_package entries (LAMMPS + analysis tool)
+#   - Detailed evaluated_entity (periodic slab with adsorbed cluster)
+
+id: "coremeta4cat:SIM_002_MD_Ni_CeO2_111"
+software_package:
+  - "LAMMPS (29 Sep 2021 stable release, OpenMP build)"
+  - "OVITO 3.7.11 (structure analysis, RDF, CNA, cluster tracking)"
+evaluated_entity:
+  - id: "coremeta4cat:SLAB_002_CeO2_111_Ni13"
+    title: "CeO2(111) surface slab with supported 13-atom Ni cluster"
+    description: "6-layer CeO2(111) p(4x4) slab (256 CeO2 formula units, 768 atoms total); bottom 3 layers fixed during MD; 13-atom cuboctahedral Ni cluster adsorbed on three-fold hollow O site; 20 Ang vacuum layer; 3D periodic boundary conditions"
+realized_plan:
+  title: "ReaxFF molecular dynamics (NVT, 800 deg C)"
+  description: "force field: ReaxFF C/H/Ni/O parametrisation (van Duin et al. 2012, DOI: 10.1021/jp210484t); ensemble: NVT with Nose-Hoover thermostat (tau = 100 fs) at 800 deg C (1073 K); integration timestep: 0.5 fs; total simulation time: 1 ns (2,000,000 steps); equilibration phase: 200 ps (400,000 steps) discarded; production phase: 800 ps (1,600,000 steps) used for analysis; sampling interval: every 1000 steps (0.5 ps); bond order cutoff: C-O 0.3, Ni-O 0.3 (fix reax/c/bonds); radial distribution functions computed with OVITO using 0.05 Ang bin width; common-neighbour analysis (CNA) to track Ni cluster crystallographic ordering"
+calculated_property:
+  - value: "1.52 J/m2"
+    description: "CeO2(111) cleavage surface energy (clean slab without Ni cluster, computed from relaxed DFT-D3 reference at 0 K, used as force field validation benchmark)"
+  - value: "-1.83 eV/atom"
+    description: "time-averaged Ni-CeO2 adhesion energy per Ni atom (13-atom cluster) relative to bulk Ni cohesive energy and clean CeO2(111) slab; computed from 800 ps production trajectory"
+  - value: "3.8 Ang"
+    description: "first-shell Ni-O coordination distance at Ni cluster / CeO2 interface (peak of Ni-O radial distribution function, production trajectory average)"
+  - value: "0.42"
+    description: "fraction of Ni atoms in direct contact with CeO2 surface (Ni-O bond order > 0.3) averaged over production trajectory; measures cluster wetting / spreading"
diff --git a/tests/data/valid/Synthesis-002.yaml b/tests/data/valid/Synthesis-002.yaml
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+---
+# Synthesis-002 -- Co-precipitation of 15 wt% NiO/CeO2 dry reforming catalyst
+# Target class: Synthesis
+#
+# Preparation method: CoPrecipitation (PrecipitationMixin + DryingMixin + CalcinationMixin).
+# realized_plan range is PreparationMethod (abstract) -- concrete subclass slots silently
+# ignored by Python loader. All method-specific parameters encoded in description.
+# See SCHEMA_REVIEW.md for the abstract-range limitation.
+#
+# Demonstrates:
+#   - Three Precursor instances (Ni salt, Ce salt, precipitant)
+#   - had_output_entity with CatalystSample
+#   - Full synthesis-level slots (support, solvent, sample_pretreatment, storage_conditions)
+#   - Rich realized_plan description encoding precipitation / drying / calcination params
+
+id: "coremeta4cat:SYNTH_002_NiO_CeO2"
+nominal_composition:
+  - "15 wt% NiO/CeO2"
+catalyst_measured_properties:
+  - "BET surface area: 42 m2/g"
+  - "NiO crystallite size: 8.4 nm (Scherrer, XRD)"
+  - "Ni loading: 14.7 wt% (ICP-AES)"
+  - "reducibility onset: 280 deg C, completion at 600 deg C (H2-TPR)"
+storage_conditions:
+  - "sealed glass vial in desiccator, ambient temperature, protected from moisture"
+solvent:
+  - "deionized water (18.2 MOhm cm, MilliQ)"
+sample_pretreatment:
+  - "in situ reduction: 5 vol% H2/N2 at 700 deg C for 1 h (10 deg C/min ramp) before DRM tests"
+had_input_entity:
+  - id: "coremeta4cat:PREC_004_Ni_NO3_6H2O"
+    title: "nickel(II) nitrate hexahydrate (Sigma-Aldrich, purity 99%)"
+    precursor_quantity:
+      - 8.72
+  - id: "coremeta4cat:PREC_005_Ce_NO3_6H2O"
+    title: "cerium(III) nitrate hexahydrate (Sigma-Aldrich, purity 99.5%)"
+    precursor_quantity:
+      - 13.03
+  - id: "coremeta4cat:PREC_006_Na2CO3"
+    title: "sodium carbonate precipitating agent (anhydrous, Sigma-Aldrich, purity 99.5%)"
+    precursor_quantity:
+      - 5.30
+had_output_entity:
+  - id: "coremeta4cat:CAT_002_NiO_CeO2"
+    title: "NiO/CeO2 dry reforming catalyst (calcined precursor)"
+    description: "15 wt% NiO on CeO2 support, co-precipitated at pH 8.5, calcined 500 deg C / 4 h, sieved to 250-500 um"
+realized_plan:
+  title: "co-precipitation"
+  description: "aqueous solutions of Ni(NO3)2 (0.5 M) and Ce(NO3)3 (0.5 M) mixed in stoichiometric ratio; precipitant: 1 M Na2CO3 solution added dropwise at 2 mL/min; target pH 8.5 maintained by feedback addition; mixing: 600 rpm mechanical stirring at 60 deg C for 2 h; aging: 12 h at 60 deg C without stirring; filtration: vacuum filtration through Whatman grade 4 filter paper; washing: 5 successive deionized water washes until conductivity < 5 uS/cm (Na+ removal); drying: 120 deg C for 12 h in static air oven; calcination: 5 deg C/min ramp to 500 deg C, isothermal hold for 4 h in static air, natural cooling"