Fig. 4: Ab initio molecular dynamics (AIMD) simulations.

Snapshots of NaCl nanocrystal (a) and LiCl structures (b), confined between two graphene sheets. AIMD-I was started with the relatively stable initial configurations and AIMD-II was started with the unstable initial configurations. Water molecules were displayed as red–white lines, while Na+, Li+, and Cl− were represented as blue, pink, and cyan spheres, respectively. The graphene walls were not shown.