diff --git a/ipsuite/__init__.pyi b/ipsuite/__init__.pyi
index 20c269fd..0f730805 100644
--- a/ipsuite/__init__.pyi
+++ b/ipsuite/__init__.pyi
@@ -2,6 +2,7 @@ from . import base
 
 # Analysis
 from .analysis import (
+    AllowedStructuresFilter,
     AnalyseDensity,
     AnalyseGlobalForceSensitivity,
     AnalyseSingleForceSensitivity,
@@ -170,6 +171,7 @@ __all__ = [
     "TemperatureCheck",
     "AnalyseDensity",
     "CollectMDSteps",
+    "AllowedStructuresFilter",
     # Calculators
     "CP2KSinglePoint",
     "ASEGeoOpt",
diff --git a/ipsuite/analysis/__init__.py b/ipsuite/analysis/__init__.py
index 28a74dd8..cf90ee96 100644
--- a/ipsuite/analysis/__init__.py
+++ b/ipsuite/analysis/__init__.py
@@ -27,6 +27,7 @@
     TemperatureCheck,
     ThresholdCheck,
 )
+from ipsuite.analysis.molecules import AllowedStructuresFilter
 from ipsuite.analysis.sensitivity import (
     AnalyseGlobalForceSensitivity,
     AnalyseSingleForceSensitivity,
@@ -63,4 +64,5 @@
     "EnergyUncertaintyHistogram",
     "AnalyseDensity",
     "CollectMDSteps",
+    "AllowedStructuresFilter",
 ]
diff --git a/ipsuite/analysis/molecules.py b/ipsuite/analysis/molecules.py
new file mode 100644
index 00000000..c9b018ae
--- /dev/null
+++ b/ipsuite/analysis/molecules.py
@@ -0,0 +1,59 @@
+import ase
+import rdkit2ase
+import tqdm
+import zntrack
+
+from ipsuite import base
+from ipsuite.geometry import BarycenterMapping
+
+
+class AllowedStructuresFilter(base.IPSNode):
+    """Search a given dataset for outliers.
+
+    Iterates all structures in the dataset, uses covalent radii to determine
+    the atoms in each molecule, and checks if the molecule is allowed.
+
+    Attributes
+    ----------
+    data : list[ase.Atoms]
+        The dataset to search.
+    molecules : list[ase.Atoms], optional
+        The molecules that are allowed.
+    smiles : list[str], optional
+        The SMILES strings of the allowed molecules.
+    """
+
+    data: list[ase.Atoms] = zntrack.deps()
+    molecules: list[ase.Atoms] = zntrack.deps(default_factory=list)
+    smiles: list[str] = zntrack.params(default_factory=list)
+    fail: bool = zntrack.params(False)
+
+    outliers: list[int] = zntrack.outs()
+
+    def run(self):
+        molecules = self.molecules + [rdkit2ase.smiles2atoms(s) for s in self.smiles]
+        mapping = BarycenterMapping()
+        self.outliers = []
+        for idx, atoms in enumerate(tqdm.tqdm(self.data)):
+            _, mols = mapping.forward_mapping(atoms)
+            for mol in mols:
+                # check if the atomic numbers are the same
+                if sorted(mol.get_atomic_numbers()) in [
+                    sorted(m.get_atomic_numbers()) for m in molecules
+                ]:
+                    continue
+                if self.fail:
+                    raise ValueError(f"Outlier found at index {idx} for molecule {mol}")
+                else:
+                    print(f"Outlier found at index {idx} for molecule {mol}")
+                self.outliers.append(idx)
+
+    @property
+    def excluded_frames(self) -> list[ase.Atoms]:
+        return [self.data[idx] for idx in self.outliers]
+
+    @property
+    def frames(self) -> list[ase.Atoms]:
+        return [
+            self.data[idx] for idx in range(len(self.data)) if idx not in self.outliers
+        ]