Fig. 1

Examples of the mean square displacements vs time. a, c Mg < − > 2H T = 2500 K, 1.98 wt% H₂O, 2 × 2 × 2 primitive supercell. b, d Si < − > Mg + 2H T = 2000K, 1.98 wt% H₂O, 2 × 1 × 1 conventional supercell. The MSD for Mg, Si, O, and H are respectively in green, blue, pink, and red. The only diffusive species is H. a and (b) are linear plots, while (c) and (d) are the log-log plots