text: Hapticity must be distinguished from denticity. Polydentate ligands coordinate via multiple coordination sites within the ligand. In this case the coordinating atoms are identified using the κ-notation, as for example seen in coordination of 1,2-bis(diphenylphosphino)ethane (PhPCHCHPPh), to NiCl as dichloro[ethane-1,2-diylbis(diphenylphosphane)-κP]nickel(II). If the coordinating atoms are contiguous (connected to each other), the η-notation is used, as e.g. in titanocene dichloride: dichlorobis(η-2,4-cyclopentadien-1-yl)titanium.