Note: Second virial coefficient of the water-hydrogen complex from an explicitly correlated potential energy surface

The second virial coefficient, B12(T), of the H 2O-H2 system has been calculated ab initio over the temperature range 200-700 K. A semi-classical method was employed with two recent accurate potential energy surfaces. The agreement with experimental data is good, although experimental error bars are much larger than the theoretical uncertainties. We show that highly correlated potentials are required for an accuracy better than 30. © 2011 American Institute of Physics.