Path sampling for atmospheric reactions: formic acid catalysed conversion of SO 3 + H 2 O to H 2 SO 4

Atmospheric reactions, hitherto studied computationally mainly with static computations in conjunction with transition state theories, can be further described via path sampling calculations. Here we report on an exploratory study of the formic acid catalysed hydrolysis of SO 3 to produce H 2 SO 4 . We demonstrate that precise measurements of rate coefficients can be obtained in principle for such reactions with an acceptable expenditure of computational resources, and that new insights into the reaction can be obtained by the analysis of the path space explored via path sampling techniques.