diff --git a/pmd_beamphysics/particles.py b/pmd_beamphysics/particles.py
index 837a959..4f7db76 100644
--- a/pmd_beamphysics/particles.py
+++ b/pmd_beamphysics/particles.py
@@ -1164,7 +1164,6 @@ def fractional_split(self, fractions: Union[float, int, list], key: str):
         and determines the split values. It then returns a list of ParticleGroup objects representing the split subsets.
 
         """
-        particles = self
 
         # Ensure fractions is a list
         if isinstance(fractions, (float, int)):