Rovibrational structure of the Xe-CO complex based on a new three-dimensional ab initio potential.

The first three-dimensional interaction potential energy surface of the Xe-CO complex is developed using the single and double excitation coupled cluster theory with noniterative treatment of triple excitations. Mixed basis sets, aug-cc-pVQZ for the C and O atoms and aug-cc-pVQZ-PP for the Xe atom, including an additional (3s3p2d2f1g) set of midbond functions are used. The calculated single point energies at five fixed r(co) values are fitted to an analytic two-dimensional potential model, and further the five model potentials are used to construct the three-dimensional potential energy surface by interpolating along (r-r(e)). Dynamical calculations with the vibrationally averaged potentials are performed to determine the energy levels and the frequencies of various rovibrational transitions. Our results agree well with the experiment. For example, the IR transitions of 508 lines are precisely reproduced with only a total rms error of 0.105 cm(-1).