We have used molecular mechanics methods to study the adsorption of R-limonene, p-menth-l-ene, p-menth-8-ene, and p-rnenthane on siliceous faujasite and zeolites Y with Si/Al = 2, which contained different cations at site SII (Nal+, Fe2+, Fe3+, and MnH). The calculations showed that the presence of double bonds on the adsorbate and the type of cation on SII determine the stability of the adsorbate zeolite complexo Host-guest interactions were dominated by electrostatic contributions, which increased with the charge on the cation at SII. The orientation of the unsaturated adsorbates in the supercage resulted from the balance between steric repulsions and the minimization of two sets of distances: those between the cation at SII and the Sp2 carbons on the guest, and those between framework oxygens and hydrogens on the guest.