Fig. 5. (a) Energy diagram obtained at the PBE/MM level of theory by QM/MM static calculations using the CI-NEB method for the single-water (pink) and assisting-water (black) reaction pathways. (b) Free energy curves obtained at the PBE/MM level of theory by QM/MM molecular dynamics calculations using the umbrella sampling method for the single-water (pink) and assisting-water (black) reaction pathways. Representation of chemical structures obtained with the umbrella sampling method for the (c) single-water and (d) the assisting-water mechanism.
