Internal rotation effects and hyperfine structure in the rotational spectrum of a water–carbon dioxide complex

Counterpoise corrected geometries of hydrated complexes

We have calculated the equilibrium geometries of the hydrated complexes, H2O.CO2, H2O.CS2,H2O.OCS, H2O.SO2, and H2O.SO3, in the electronic ground state. We have used the coupled cluster with singles, doubles, and perturbative triples ab initio method with a correlation consistent augmented triple-zeta basis set. We find that a counterpoise corrected optimization scheme is important for an accurate description of the geometries. These high level ab initio calculated geometries are of comparable quality to those obtained experimentally.