Accurate intermolecular ground state potential of the Ar-N-2 complex

The ground state potential energy surface of the Ar-N-2 van der Waals compl ex is evaluated using the coupled cluster singles and doubles model, includ ing connected triples corrections (CCSD(T)) and the aug-cc-pVTZ basis set e xtended with midbond functions. From the calculated ab initio potential the rovibronic spectroscopic properties are determined and compared with the a vailable experimental data. Considerable improvement is obtained when four of the potential parameters are refined based on the Ar-N-14(2) rotational transition frequencies. The small discrepancies remaining demonstrate that the coupled cluster method can be used to predict the spectroscopic propert ies of van der Waals complexes. (C) 1999 American Institute of Physics. [S0 021-9606(99)30417-7].