The interface of electronic structure and dynamics for reactions in solution

We compare two systematic approaches to the calculation of reaction rates in liquid solutions: the separable equilibrium solvation (SES) approximation and the equilibrium solvation path (ESP) approximation. These approaches are tested for two reactions, ClCH3+NH3→Cl−+H3CNH3+ (R1) and NH4+…N′H3→NH3…N′H4+ (R2), both in aqueous solution. The first reaction illustrates the importance of variational optimization of the transition state, and the second illustrates the importance of tunneling. Free energies of solvation are calculated by the Solvation Model 5. All calculations are carried out by the new AMSOLRATE program, which is an interface of the AMSOL and POLYRATE programs.