Fig. 7. 2D free energy surfaces, involving Cr–Cl, Cr–Cr, Cr–Mg distance and electric field, E, experienced by (a) Cl, (b) Cr, and (c) Mg with corresponding Marcus parabolas (solid lines are parabolic fits and dots are actual data), describing chloride exchange around Cr3+ and dissociation of the Cr–Cr and Cr–Mg dimers. The lines with arrows are the Marcus pathways showing how reorganization of ionic media causes electric field rearrangement and drives the exchange and dissociation events. (d) The corresponding 1D free energy profiles.
