We evaluate highly accurate ab initio ground-state intermolecular potential-energy surfaces (IPESs) for weakly bound molecular complexes. Thousands of interaction energies are calculated with the coupled cluster CCSD(T) method and Dunning’s basis sets extended with midbond functions. To check the quality of the potentials fits are carried out, analytical functions obtained and the corresponding intermolecular rovibrational levels are evaluated. The RMSEs with respect to experiment confirm the very high accuracy of the potentials. In the Figs. CO-N2 IPES.