Figure 8.

MD simulation results showing the basal spacing dependence (d₀₀₁) on (a) the coordination environment of K⁺, (b) hydrogen bond populations, and (c) diffusion coefficients of water. (a) First-shell coordination of K⁺ to oxygens, belonging to either water (O-water, red) or birnessite (O-BIR, blue).The coordination numbers were calculated from the radial distribution functions up to the minima of the first coordination shell at 0.35 nm (Figure S9). (b) Number of hydrogen bonds between water and birnessite. (c) Diffusion coefficients of water (red) and K⁺ (blue). Dashed vertical lines indicate ideal 1 W and 2 W hydration states.