Intermolecular potential energy surface and second virial coefficients for the water–CO2 dimer

A five-dimensional potential energy surface is calculated for the interaction of water and CO2, using second-order Møller–Plesset perturbation theory and coupled-cluster theory with single, double, and perturbative triple excitations. The correlation energy component of the potential energy surface is corrected for basis set incompleteness. In agreement with previous studies, the most negative interaction energy is calculated for a structure with C2v symmetry, where the oxygen atom of water is close to the carbon atom of CO2. Second virial coefficients for the water–CO2 pair are calculated for a range of temperatures, and their uncertainties are estimated. The virial coefficients are shown to be in close agreement with the available experimental data.