Fig. 1

Atomic structures. a Top and b side view of a 2×2 ReS2 unit cell. The grey balls represent Re atoms and the yellow balls represent S atoms. The dashed line represents the unit cell boundary. c All stable Li adsorption sites on a 2×2 ReS2 unit cell. Green balls represent Li at the α sites and blue balls represent Li at the β sites. Note that all of these sites were found using randomly placing an Li ion over a 2×2 ReS2 supercell and relaxing the structure but are clubbed into a single 2×2 supercell in the figure for the convenience of visualization