Several factors influence the crystal field splitting energy, including:
The nature of the metal ion: Different metals have different intrinsic properties that affect Δ. The type of ligands: Strong field ligands such as CN- and CO cause a larger splitting compared to weak field ligands like H2O and Cl-. The geometry of the complex: Octahedral, tetrahedral, and square planar geometries all result in different splitting patterns and magnitudes.