FT-IR spectra of N₂, O₂, and D₂ adsorbed on the dehydrated LiX, NaLiX, and NaX zeolites are studied at 77 K. The measured shifts of the bond-stretching frequencies and the integrated vibrational fundamental band intensities for admolecules are compared with the results of the recent high-level ab initio calculations. The effective electric fields in zeolite cavities are also reported.