Figure 6: Free-energy profiles for proton hole transfer in the narrow and wide slit pores.
Free-energy profiles for proton hole transfer in the narrow and wide slit pores compared with the homogeneous bulk environment at the same thermodynamic conditions as a function of the transfer coordinate δ including and excluding proton hole rattling events (see text) in a and b, respectively. The free-energy signature of the trapped Zundel intermediate Z is highlighted using a black ellipse and the total free-energy profile in the wide pore is additionally split into contributions due to E and T/B states. The definitions of the E, T, B and Z charge defect states are provided in Fig. 5 (see also Fig. 4) and the horizontal dashed line marks the corresponding thermal energy.
