Abstract: The intermolecular potential energy surface and dipole moment surface for He-N₂O have been calculated by using the forth-order Moller-Plesset（MP4） perturbation theory with a large basis set （AVTZ） augmenting with the midpoint bond function set 3s3p2d. The two-dimensional discrete variable representation method was employed to calculate the ro-vibrational energy level for ⁴He-N₂O and ³He-N₂O. The transiton intensities of the rotational transitions in the ν₃ region of N₂O for the ground vibrational state have been calculated and compared with the observed results.

Key words: He-N₂O, Dipole moment, DVR, Ro-vabrational energy levels, Transition intensity