Fig. 2.
Adiabatic potential energy surface as a function of O3′-P1A and P1A-O3A distances. (a) Three-dimensional plot of the potential energy surface. The reaction path is designated by the red dots; the blue dot is the optimized ground state structure, which is connected to the local minimum state through the proton transfer process by the blue curve. (b) Contour plot of the potential energy surface in the region 1.6 ≤ O3′-P1A ≤ 2.6 Å and 1.6 ≤ P1A-O3A ≤ 2.7 Å. The TS can be identified at RO3′-P1A = 2.2 Å and RP1A-O3A = 1.9 Å. Energies are in kilocalorie per mole.