Fig. 1. Dissociation of NaCl in water.

a Free energy profiles ΔG(x) along the interionic distance x, obtained from a 1 μs long unbiased MD trajectory at 293 K (orange line) and 1000 × 1 ns TMD runs (blue line). Error bars are given in Supplementary Fig. 2. Also shown is the average work 〈W(x)〉 calculated from the TMD simulations (dashed black line). b Friction profile Γ(x) (red) obtained from dcTMD after Gaussian smoothing together with the average number of water molecules (black), that connect the Na⁺ and Cl⁻ ions in a common hydration shell³⁴.